Chapter 1 Practice Problems (Practice – no credit) Due: 11:59pm on Wednesday, February 5, 2014 You will receive no credit for items you complete after the assignment is due. Grading Policy Curved Motion Diagram The motion diagram shown in the figure represents a pendulum released from rest at an angle of 45 from the vertical. The dots in the motion diagram represent the positions of the pendulum bob at eleven moments separated by equal time intervals. The green arrows represent the average velocity between adjacent dots. Also given is a “compass rose” in which directions are labeled with the letters of the alphabet. Part A What is the direction of the acceleration of the object at moment 5? Enter the letter of the arrow with this direction from the compass rose in the figure. Type Z if the acceleration vector has zero length. You did not open hints for this part. ANSWER: Incorrect; Try Again Part B What is the direction of the acceleration of the object at moments 0 and 10? Enter the letters corresponding to the arrows with these directions from the compass rose in the figure, separated by commas. Type Z if the acceleration vector has zero length. You did not open hints for this part. ANSWER: Incorrect; Try Again PSS 1.1 Motion Diagrams Learning Goal: To practice Problem-Solving Strategy 1.1 for motion diagram problems. A car is traveling with constant velocity along a highway. The driver notices he is late for work, so he stomps down on the gas pedal and the car begins to speed up. The car has just achieved double its directions at time step 0, time step 10 = initial velocity when the driver spots a police officer behind him and applies the brakes. The car then slows down, coming to rest at a stoplight ahead. Draw a complete motion diagram for this situation. PROBLEM-SOLVING STRATEGY 1.1 Motion diagrams MODEL: Represent the moving object as a particle. Make simplifying assumptions when interpreting the problem statement. VISUALIZE: A complete motion diagram consists of: The position of the object in each frame of the film, shown as a dot. Use five or six dots to make the motion clear but without overcrowding the picture. More complex motions may need more dots. The average velocity vectors, found by connecting each dot in the motion diagram to the next with a vector arrow. There is one velocity vector linking each set of two position dots. Label the row of velocity vectors . The average acceleration vectors, found using Tactics Box 1.3. There is one acceleration vector linking each set of two velocity vectors. Each acceleration vector is drawn at the dot between the two velocity vectors it links. Use to indicate a point at which the acceleration is zero. Label the row of acceleration vectors . Model It is appropriate to use the particle model for the car. You should also make some simplifying assumptions. v 0 a Part A The car’s motion can be divided into three different stages: its motion before the driver realizes he’s late, its motion after the driver hits the gas (but before he sees the police car), and its motion after the driver sees the police car. Which of the following simplifying assumptions is it reasonable to make in this problem? During each of the three different stages of its motion, the car is moving with constant A. acceleration. B. During each of the three different stages of its motion, the car is moving with constant velocity. C. The highway is straight (i.e., there are no curves). D. The highway is level (i.e., there are no hills or valleys). Enter all the correct answers in alphabetical order without commas. For example, if statements C and D are correct, enter CD. ANSWER: Correct In addition to the assumptions listed above, in the rest of this problem assume that the car is moving in a straight line to the right. Visualize Part B In the three diagrams shown to the left, the position of the car at five subsequent instants of time is represented by black dots, and the car’s average velocity is represented by green arrows. Which of these diagrams best describes the position and the velocity of the car before the driver notices he is late? ANSWER: Correct Part C Which of the diagrams shown to the left best describes the position and the velocity of the car after the driver hits the gas, but before he notices the police officer? ANSWER: Correct A B C A B C Part D Which of the diagrams shown to the left best describes the position and the velocity of the car after the driver notices the police officer? ANSWER: Correct Part E Which of the diagrams shown below most accurately depicts the average acceleration vectors of the car during the events described in the problem introduction? ANSWER: A B C Correct You can now draw a complete motion diagram for the situation described in this problem. Your diagram should look like this: Measurements in SI Units Familiarity with SI units will aid your study of physics and all other sciences. Part A What is the approximate height of the average adult in centimeters? Hint 1. Converting between feet and centimeters The distance from your elbow to your fingertips is typically about 50 . A B C cm ANSWER: Correct If you’re not familiar with metric units of length, you can use your body to develop intuition for them. The average height of an adult is 5 6.4 . The distance from elbow to fingertips on the average adult is about 50 . Ten (1 ) is about the width of this adult’s little finger and 10 is about the width of the average hand. Part B Approximately what is the mass of the average adult in kilograms? Hint 1. Converting between pounds and kilograms Something that weighs 1 has a mass of about . ANSWER: Correct Something that weighs 1 has a mass of about . This is a useful conversion to keep in mind! ± A Trip to Europe 100 200 300 cm cm cm feet inches cm mm cm cm pound 1 kg 2 80 500 1200 kg kg kg pound (1/2) kg Learning Goal: To understand how to use dimensional analysis to solve problems. Dimensional analysis is a useful tool for solving problems that involve unit conversions. Since unit conversion is not limited to physics problems but is part of our everyday life, correct use of conversion factors is essential to working through problems of practical importance. For example, dimensional analysis could be used in problems involving currency exchange. Say you want to calculate how many euros you get if you exchange 3600 ( ), given the exchange rate , that is, 1 to 1.20 . Begin by writing down the starting value, 3600 . This can also be written as a fraction: . Next, convert dollars to euros. This conversion involves multiplying by a simple conversion factor derived from the exchange rate: . Note that the “dollar” unit, , should appear on the bottom of this conversion factor, since appears on the top of the starting value. Finally, since dollars are divided by dollars, the units can be canceled and the final result is . Currency exchange is only one example of many practical situations where dimensional analysis may help you to work through problems. Remember that dimensional analysis involves multiplying a given value by a conversion factor, resulting in a value in the new units. The conversion factor can be the ratio of any two quantities, as long as the ratio is equal to one. You and your friends are organizing a trip to Europe. Your plan is to rent a car and drive through the major European capitals. By consulting a map you estimate that you will cover a total distance of 5000 . Consider the euro-dollar exchange rate given in the introduction and use dimensional analysis to work through these simple problems. Part A You select a rental package that includes a car with an average consumption of 6.00 of fuel per 100 . Considering that in Europe the average fuel cost is 1.063 , how much (in US dollars) will you spend in fuel on your trip? Express your answer numerically in US dollars to three significant figures. You did not open hints for this part. ANSWER: US dollars USD 1 EUR = 1.20 USD euro US dollars USD 3600 USD 1 1.00 EUR 1.20 USD USD USD ( )( ) = 3000 EUR 3600 USD 1 1.00 EUR 1.20 USD km liters km euros/liter Part B How many gallons of fuel would the rental car consume per mile? Express your answer numerically in gallons per mile to three significant figures. You did not open hints for this part. ANSWER: Part C This question will be shown after you complete previous question(s). Score Summary: Your score on this assignment is 0%. You received 0 out of a possible total of 0 points. Cost of fuel = USD gallons/mile
Chapter 06 Reading Questions Due: 11:59pm on Friday, May 23, 2014 You will receive no credit for items you complete after the assignment is due. Grading Policy Chapter 6 Reading Quiz Question 17 Part A Which of the following represents an example of intraspecific exploitation competition? ANSWER: Chapter 6 Reading Quiz Question 3 Part A A species’s realized niche _____. ANSWER: Chapter 6 Reading Quiz Question 2 Part A Two species of ant compete for limited resources in a front yard, until only one species is able to remain. This is an example of _____. ANSWER: Hungry and fighting for a meal, a jackal quickly consumes the carcass of a young antelope while fighting off the feeding efforts of a vulture. Two species of worker ants converge on pieces of a donut left behind from the people in the park. The leaves of the huge hickory tree overshadow the young hickory tree saplings struggling for light just below. Spotting a fresh source of grasses, the large male bison moves over to graze, pushing the smaller bison out of the way. is smaller than the fundamental niche because of the constraints of competition is broader than a species’s fundamental niche does not overlap with similar species includes environmental conditions that are not included in the fundamental niche Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 1 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 20 Part A In which of the following situations would we expect a parasite to spread the fastest? ANSWER: Chapter 6 Reading Quiz Question 6 Part A Many plants have evolved adaptations to discourage herbivore feeding. Which one of the following is an example of such coevolution between bison and prairie plants? ANSWER: Chapter 6 Reading Quiz Question 5 Part A When predators selectively prey on the old and sick members of a prey population, they _____. ANSWER: mutualism intraspecific competition the competitive exclusion principle niche differentiation concentrated hosts with slowly moving vectors widely dispersed hosts with rapidly moving vectors concentrated hosts with rapidly moving vectors widely dispersed hosts with slow-moving vectors the ability to regrow after a wildfire thorns the production of nutritious fruits longer and thicker roots Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 2 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 21 Part A Cattle egrets are large white birds that follow grazing cattle. The cattle disturb the grass and stir up insects upon which the egrets feed. The cattle do not seem to mind the birds and gain nothing from this relationship. This relationship between cattle and cattle egrets is a type of _____. ANSWER: Chapter 6 Reading Quiz Question 8 Part A Which of the following is a mutualistic relationship that has a significant effect on an entire ecological community? ANSWER: Chapter 6 Reading Quiz Question 7 Part A Which one of the following relationships would be considered a win/win? ANSWER: cause the overall health of the prey population to increase illustrate the process of prey switching increase the likelihood of parasitic infections of the prey cause the overall health of the prey population to decrease parasitism commensalism mimicry mutualism Polar bears are the top predator influencing the abundance of seals and sea lions in a region. Hermit crabs inhabit the abandoned shells of marine snails that died long ago. Fungus-plant root associations benefit most of the plants living in a prairie. Mosquitoes function as a vector in the widespread transmission of malaria to people living in Ecuador. Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 3 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 23 Part A In examining a terrestrial food web, we expect that the _____. ANSWER: Chapter 6 Reading Quiz Question 22 Part A Energy is lost as it moves from one trophic level to the next because _____. ANSWER: Chapter 6 Reading Quiz Question 11 Part A The research on the reintroduction of wolves into Yellowstone National Park reveals that in this ecosystem, wolves represent _____. ANSWER: mutualism predation parasitism commensalism biomass of primary consumers exceeds the biomass of producers number of secondary consumers exceeds the number of producers biomass of primary consumers exceeds the biomass of secondary consumers number of tertiary consumers exceeds the number of secondary consumers one trophic level does not consume the entire trophic level below it some of the calories consumed drive cellular activities and do not add mass some ingested materials are undigested and eliminated All of the listed responses are correct. Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 4 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 10 Part A Overhunting of deer followed by a very difficult winter caused the deer population on an island to drop by 80%. In the next two years, visitors to the island were surprised to see many young trees sprouting up at the edges of the forest. This change in the number of saplings as a result of the decline of the deer population represents _____. ANSWER: Chapter 6 Reading Quiz Question 24 Part A The May 18, 1980, eruption of Mount Saint Helens blasted away soil and produced massive mudflows that scoured the adjacent region down to bare rock. Pumice rock that covered the area is eroding down to smaller gravel. This situation represents _____. ANSWER: Chapter 6 Reading Quiz Question 15 Part A In some ecosystems, succession increases the chance of disturbance. In these ecosystems, _____. a keystone producer a keystone herbivore a vital primary consumer a keystone predator a trophic cascade a decline in trophic level efficiency the emergence of a new ecological community a loss of a trophic level from a food web primary succession with the removal of all ecological legacies secondary succession with the removal of all ecological legacies secondary succession with several ecological legacies primary succession with several ecological legacies Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 5 of 7 5/21/2014 8:01 PM ANSWER: Chapter 6 Reading Quiz Question 12 Part A A forest is logged, leaving behind the seeds and saplings of many shrubs and trees. These seeds and saplings represent _____. ANSWER: Chapter 6 Reading Quiz Question 13 Part A During primary succession, populations of different species replace one another over time because of _____. ANSWER: Chapter 6 Reading Quiz Question 14 Part A Which one of the following represents a climax community in southern Alaska? ANSWER: ecosystems begin again with primary succession climax communities are expected climax communities may not occur disturbances usually result in virtually no ecological legacy ecological legacies a climax community primary succession pioneer species migration facilitation competition All of the listed responses are correct. Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 6 of 7 5/21/2014 8:01 PM Chapter 6 Reading Quiz Question 9 Part A In general, _____. ANSWER: Score Summary: Your score on this assignment is 0.0%. You received 0 out of a possible total of 19 points. the group of species associated with a white spruce forest lichens and mosses that colonize exposed rock birch and alder trees herbs and a few low shrubs that replace lichens and mosses food webs usually have 8-10 trophic levels food webs are interconnected food chains food chains consist of many interrelated food webs food webs consist of either consumers or producers Chapter 06 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 7 of 7 5/21/2014 8:01 PM
Chapter 06 Homework Due: 11:59pm on Friday, May 23, 2014 You will receive no credit for items you complete after the assignment is due. Grading Policy Concept Review: Species Interactions Can you identify the type of species interaction that each label describes? Part A Drag each description to the appropriate bin. ANSWER: Activity: Food Webs Click here to complete this activity. Then answer the questions. Part A In an ecosystem, phytoplankton are _____. ANSWER: Chapter 06 Homework http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 1 of 9 5/21/2014 8:01 PM Correct Autotrophs, such as phytoplankton, are producers. Part B An earthworm that feeds on the remains of plants and animals is acting as a _____. ANSWER: Correct The earthworm is feeding on the remains of dead organisms. Part C When a human eats a steak, the human is acting as a _____. ANSWER: Correct By feeding on a primary consumer, the human is acting as a secondary consumer. Part D A cow eating grass is an example of a _____. ANSWER: Correct By feeding on a producer, the cow is acting as a primary consumer. Part E primary consumers tertiary consumers detritivores producers secondary consumers tertiary consumer secondary consumer producer detritivore primary consumer primary consumer detritivore secondary consumer producer tertiary consumer detritivore producer tertiary consumer secondary consumer primary consumer Chapter 06 Homework http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 2 of 9 5/21/2014 8:01 PM A seal that just ate a clam is eaten by a shark. The shark is acting as a _____. ANSWER: Correct The shark that ate the seal that ate the clam that ate the algae is the tertiary consumer. Activity: Pyramids of Production Click here to complete this activity. Then answer the questions. Part A _____ are secondary consumers. ANSWER: Correct Secondary consumers are animals that eat other animals; thus, they are carnivores. Part B Approximately _____% of the energy at one trophic level is passed on to the next highest trophic level. ANSWER: Correct Approximately 5–10% of the energy at one trophic level is passed on to the next highest trophic level. producer primary consumer tertiary consumer secondary consumer detritivore Producers Herbivores Plants Cows Carnivores 0–5 5–10 10–15 15–20 90–100 Chapter 06 Homework http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 3 of 9 5/21/2014 8:01 PM Part C 10,000 kcal of producer could support approximately _____ kcal of tertiary consumer. ANSWER: Correct This is the number of kcal of tertiary consumer that could be supported. Activity: Primary Succession Click here to complete this activity. Then answer the question. Part A Which of these is a starting point for primary succession? ANSWER: Correct Such a surface lacks any life and is thus a starting point for primary succession. Part B The first colonizing organisms during primary succession tend to be: ANSWER: 1,000 100 10 1 0 a surface exposed by a retreating glacier abandoned farmland an abandoned city a neglected yard none of these is a starting point for primary succession small shrubs trees lichens and mosses herbs Chapter 06 Homework http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 4 of 9 5/21/2014 8:01 PM Correct After the glacier retreats, bare ground is eventually colonized by lichens and mosses. Part C Which one of the following is a general characteristic of plants that are early colonizers during primary succession? ANSWER: Correct After the glacier retreats, bare ground is eventually colonized by lichens and mosses, then by deciduous trees with wind-borne seeds. Concept Review: Secondary Succession Can you order the steps of secondary succession? Part A Order the labels in the flowchart to complete the model of secondary succession as observed in a deciduous forest of eastern North America. ANSWER: Current Events: In Yellowstone, Killing One Kind of Trout to Save Another (New York Times, 8/23/2011) Read this New York Times article and then answer the questions. In Yellowstone, Killing One Kind of Trout to Save Another (8/23/2011) Registration with The New York Times provides instant access to breaking news on NYTimes.com. To register, go to http://www.nytimes.com/register. Visit http://www.nytimes.com/content/help/rights/terms/terms-of-service.html to review the current NYT Terms of Service. Part A Which of the following would be the best discovery regarding the Judas fish? ANSWER: plants are able to fix their own nitrogen plants can outcompete other plants that invade the area plants have wind-dispersed seeds plants are shade-tolerant Chapter 06 Homework http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 5 of 9 5/21/2014 8:01 PM Part B Which of the following is true? ANSWER: Part C Why is protecting cutthroat trout in Yellowstone so important? ANSWER: Part D Which of the following is true? ANSWER: Part E Why don’t bears in Yellowstone eat lake trout? ANSWER: Part F How did rainbow trout become established worldwide? ANSWER: Learning where lake trout feed. Learning where lake trout hibernate. Learning where lake trout spawn. Learning where lake trout migrate to during fall. Officials are working only in certain areas to eliminate lake trout. Officials are working to eliminate lake trout throughout Wyoming. Officials are working to eliminate lake trout throughout the Great Lakes. All states in the U.S. are working to eliminate lake trout. Because many other species depend on cutthroat trout. Because local people depend on cutthroat trout for food. Because Yellowstone is the only place cutthroat trout are found. Because cutthroat trout are listed as a threatened species. Cutthroat trout are to Yellowstone Lake as rainbow trout are to Yellowstone Lake. Cutthroat trout are to Yellowstone Lake as Asian carp are to the Great Lakes. Lake trout are to Yellowstone Lake as see lamprey are to the Great Lakes. Lake trout are to the Great Lakes as Asian carp are to the Yellowstone Lake. They don’t like the taste. They cannot find them. Lake trout skin is too tough. Lake trout are too small for bears to be interested. Chapter 06 Homework http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 6 of 9 5/21/2014 8:01 PM Current Events: In Thailand, Love of Food Carries Deadly Risks (New York Times, 4/25/2011) Read this New York Times article and then answer the questions. In Thailand, Love of Food Carries Deadly Risks (4/25/2011) Registration with The New York Times provides instant access to breaking news on NYTimes.com. To register, go to http://www.nytimes.com/register. Visit http://www.nytimes.com/content/help/rights/terms/terms-of-service.html to review the current NYT Terms of Service. Part A Rather than stop eating fish, what should Thai people do to eliminate the risk of liver fluke infection? ANSWER: Part B Liver flukes are transmitted through which of the following? ANSWER: Part C Getting rid of which of the following would help decrease the population of liver flukes? ANSWER: Part D Pla som is a unique dish because it is what? ANSWER: Part E Due to warming oceans caused by climate change. Natural process of migration. Accidental introduction via ships. Purposeful stocking. Consume ethyl alcohol while eating fish. Add more garlic. Cook it thoroughly. Pick the flukes out by hand. urine saliva feces blood rats mosquitoes frogs snails pickled frozen fermented blanched Chapter 06 Homework http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 7 of 9 5/21/2014 8:01 PM You have liver flukes. What are your chances of getting liver cancer? ANSWER: Part F You are a scientist studying liver flukes in Thailand. Where should you look for them? ANSWER: ABC News Video: The Cuttlefish Watch the ABC News video (2:20 minutes). Then answer the questions below. Part A The changes to the cuttlefish’s skin are related to _______. ANSWER: Correct Part B Camouflage contributes to the cuttlefish’s survival by enabling it to _______. 1-5% 5-10% 10-15% 15-20% The northwestern part of the country. The southeastern part of the country. The southwestern part of the country. The northeastern part of the country. camouflage elimination of waste reproductive strategies feeding behavior Chapter 06 Homework http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 8 of 9 5/21/2014 8:01 PM ANSWER: Correct Part C Cuttlefish placed in a sandy environment with white rocks will camouflage their skin in a pattern called _______. ANSWER: Correct Part D In the presence of a black-and-white striped background, a cuttlefish was observed to _______. ANSWER: Correct Part E Which question was raised but not answered in the video? ANSWER: Correct Score Summary: Your score on this assignment is 48.5%. You received 16 out of a possible total of 33 points. sneak up on prey mimic poisonous species hide from predators warn potential predators that it is poisonous universal camouflage disruptive camouflage warning coloration camouflage tide-pool camouflage move its arm to match the orientation of the stripes turn completely white and hide in the white stripe turn completely black and hide in the black stripe exhibit the exact striping pattern of its surroundings Why does the cuttlefish change its skin pattern? What happens when a cuttlefish is placed in an unnatural environment? Is the cuttlefish able to grow a protective shell? How do cuttlefish camouflage themselves even though they are colorblind? Chapter 06 Homework http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 9 of 9 5/21/2014 8:01 PM
ECON 101 FALL 2015 EXAM 1 NAME:______________________________ 1. Suppose the price elasticity of demand for cheeseburgers equals 1.37. This means the overall demand for cheeseburgers is: A) price elastic. B) price inelastic. C) price unit-elastic. D) perfectly price inelastic. 2. The price elasticity of demand for skiing lessons in New Hampshire is less than 1.00. This means that the demand is ______ in New Hampshire. A) price elastic B) price inelastic C) price unit-elastic D) perfectly price elastic 3. If the demand for textbooks is price inelastic, which of the following would explain this? A) Many alternative textbooks can be used as substitutes. B) Students have a lot of time to adjust to price changes. C) Textbook purchases consume a large portion of most students’ income. D) The good is a necessity. 4. A major state university in the South recently raised tuition by 12%. An economics professor at this university asked his students, “Due to the increase in tuition, how many of you will transfer to another university?” One student out of about 300 said that he or she would transfer. Based on this information, the price elasticity of demand for education at this university is: (Hint: one out of 300 is how much of a percentage change? Which percentage change is greater – tuition or transfer? Apply the basic formula for elasticity that I put on the board a few times.) A) one. B) highly elastic. C) highly inelastic. D) zero. 5. Suppose the price elasticity of demand for fishing lures equals 1 in South Carolina and 0.63 in Alabama. To increase revenue, fishing lure manufacturers should: (Hint: If the demand for a product is inelastic, the price can go up and you’ll still buy it, since there are no or few substitutes. If the demand for a product is elastic, the price can go up and you’ll probably walk away from it, since substitutes are available. How might this info impact the pricing strategies of firms?) A) lower prices in each state. B) raise prices in each state. C) lower prices in South Carolina and raise prices in Alabama. D) leave prices unchanged in South Carolina and raise prices in Alabama. Read your syllabus and answer questions 6 through 10: 6. T or F: Disruptive classroom behavior includes the following: chatting with fellow students, use of electronic devices such as laptops, tablets, notebooks, and cell phones, reading or studying during class, sleeping, arriving late, departing early, studying for another class, or in any other way disturbing the class. 7. T or F: It’s OK to use my computer in class or play with my phone. There is no penalty attached to these activities and Keiser doesn’t really mind. 8. T or F: It’s OK to show up late for class and disrupt one of Keiser’s swashbuckling lectures. 9. T or F: Attendance is highly optional since it doesn’t impact my final course grade. 10. T or F: I should blow off the career plan/business plan assignment in this course because it’s unimportant to my future and not worth many points. 11. Jacquelyn is a student at a major state university. Which of the following is not an example of an explicit, or direct, cost of her attending college? A) Tuition B) Textbooks C) the salary that she could have earned working full time D) computer lab fees 12. The two principles of tax fairness are: A) the minimize distortions principle and the maximize revenue principle. B) the benefits principle and the ability-to-pay principle. C) the proportional tax principle and the ability-to-pay principle. D) the equity principle and the efficiency principle. 13. The benefits principles says: A) the amount of tax paid depends on the measure of value. B) those who benefit from public spending should bear the burden of the tax that pays for that spending. C) those with greater ability to pay should pay more tax. D) those who benefit from the tax should pay the same percentage of the tax base as those who do not benefit. 14. A tax that rises less than in proportion to income is described as: (Hint: This would have more of a negative impact on lower income earners vs. higher income earners.) A) progressive. B) proportional. C) regressive. D) structural. 15. The U.S. income tax is _______, while the payroll tax is _______. (Hint: Think income tax vs. Social Security tax.) A) progressive; progressive C) regressive; progressive B) progressive; regressive D) regressive; regressive 16. Who is currently leading in the polls to receive the Republican nomination as that party’s presidential candidate? A) Qasem Soleimani B) Abu Bakr al-Baghdadi C) Osama bin Laden D) Donald J. Trump 17. The single most important thing I’ve learned in class this term is: A) stay in frickin’ school B) stay in school and make a plan for life and my career C) the use of cheese for skyscraper construction D) both A and B above 18. Market equilibrium occurs when: A) there is no incentive for prices to change in the market. B) quantity demanded equals quantity supplied. C) the market clears. D) all of the above occur. 19. Excess supply occurs when: (Hint: Draw a supply and demand graph! Think about price ceilings and floors and the graphs of these we discussed in class.) A) the price is above the equilibrium price. B) the quantity demanded exceeds the quantity supplied. C) the price is below the equilibrium price. D) both b and c occur. 20. The single most important thing I’ve learned in class this term is: a. stay in school and look into either a study abroad or internship experience b. stay in school and make a plan for life and my career c. the untimely demise of Cecil the lion in Zimbabwe d. both a. and b. above 21. According to the textbook definition, mainstream microeconomics generally focuses on a. how individual decision-making units, like households and firms, make economic decisions. b. the performance of the national economy and policies to improve this performance. c. the relationship between economic and political institutions. d. the general level of prices in the national economy. 22. Which of the following is the best summary of the three basic economic questions? a. Who? Why? and When? b. What? How? and Who? c. When? Where? and Why? d. What? Where? and Who? 23. Which of the following is not one of the basic economic resources? a. land b. labor c. capital d. cheese e. entrepreneurship 24. The largest country in the Arabian Peninsula and home to the cities of Riyadh, Jeddah, Mecca, and Medina is: a. The Kingdom of Saudi Arabia b. California c. Spain d. Kentucky 25. T or F: The law of demand explains the upward slope of the supply curve. 26. In economics, a “marginal” value refers to: a. the value associated with an important or marginal activity. b. a value entered as an explanatory item in the margin of a balance sheet or other accounts. c. the value associated with one more unit of an activity. d. a value that is most appropriately identified in a footnote. 27. A government mandated price that is below the market equilibrium price is sometimes called. . . (Hint: Draw a graph again and think about what the government is trying to accomplish.) a. a price ceiling. b. a price floor. c. a market clearing price. d. a reservation price. 28. T or F: Entering the US job market without any education or training is crazy and should be avoided. Stay in frickin’ school, baby! 29. The law of demand states that, other things equal: a. as the price increases, the quantity demanded will increase. b. as the price decreases, the demand curve will shift to the right. c. as the price increases, the quantity demanded will decrease. d. none of the above. 30. The law of supply says: a. other things equal, the quantity supplied of a good is inversely related to the price of the good. b. other things equal, the supply of a good creates its own demand. c. other things equal, the quantity supplied of a good is positively related to the price of the good. d. none of the above. 31. A perfectly inelastic demand curve is: a. horizontal. b. downward sloping. c. upward sloping. d. vertical. 32. A trade-off involves weighing costs and benefits. a. true b. false 33. A perfectly elastic demand curve is: a. horizontal. b. downward sloping. c. upward sloping. d. vertical. 34. The second most important thing I’ve learned in class this term is: a. despair is not an option b. Donald J. Trump’s hair is real c. the use of cheese for skyscraper construction d. none of the above 35. T or F: Virtually any news item has important economic dimensions and consequences. 36. T or F: When studying economics, always think in terms of historical context. 37. This popular Asian country is populated by 1.3 billion people, has the world’s second largest economy, and uses a language that’s been in continuous use for nearly 5,000 years: a. Kentucky b. California c. Spain d. China 38. T or F: The top priority in my life right now should be my education and an internship experience. Without these, the job market is going to kick my butt! 39. Which of the following is a key side effect generated by the use of price ceilings? a. black markets b. products with too high of quality c. an excess supply of a good d. too many resources artificially channeled into the production of a good 40. Which of the following is NOT one of the four basic principles for understanding individual choice? a. Resources are scarce. b. The real cost of something is the money that you must pay to get it. c. “How much?” is a decision at the margin. d. People usually take advantage of opportunities to make themselves better off. 41. A hot mixture of pan drippings, flour, and water is commonly known as: a. interest rates and expected future real GDP. b. interest rates and current real GDP. c. inflation and expected future real GDP. d. gravy. 42. The example we used in class when discussing the inefficiency of quantity quotas was: a. Uber b. General Electric c. AT&T d. the KSU marching band 43. The term we learned in class signifying a key method of non-price competition is: a. excess supply chain management b. arbitrage c. swashbuckling d. product differentiation 44. When discussing market failure and the role of regulation in class, which company/product did we use as an example? a. Pabst Blue Ribbon b. JetBlue c. Blue Bell d. Blue Apron 45. Governments may place relatively high sales taxes on goods such as alcohol and tobacco because: a. such taxes are a significant source of revenue b. such goods exhibit inelastic demand c. such taxes may discourage use of these products d. all of the above 46. When discussing the cost of higher education in class, which country did we cite as an example of one that offers free college for qualifying students? a. USSR b. Rhodesia c. Czechoslovakia d. Germany 47. Which of the following is not an example of market failure we discussed in class? a. externalities b. public goods c. fungible goods d. common pool resources e. equity 48. T or F: As we discussed in class, the real reason why the US has lost jobs to China is the “most favored nation” (MFN) trading status granted to China by the US back in the 1980s. 49. The dude we talked about in class who coined the expression “invisible hand” and promoted self-interest and competition in his famous book “The Wealth of Nations” is: a. Abu Bakr al-Baghdadi b. Ali Khamenei c. Donald J. Trump d. Adam Smith 50. When studying for your final exams and attempting to allocate your limited time among several subjects in order to maximize your course grades (recall, we talked about this example during the first week of class), you’re almost unconsciously engaging in a form of: a. fraud b. miscellaneous serendipity b. mitosis d. marginal analysis
Most of the energy consumed in food is spent maintaining … Read More...
Berkeley College International Economics Quiz 1 Student name: Class & Session (Type all your answers in the parenthesis) Multiple Choice Questions (75 points) 1. The person credited with the first systematic expression of the principle of comparative advantage was ( ) A. Alan Greenspan. B. John Maynard Keynes. C. David Ricardo. D. Adam Smith. 2. A regulation that sets the highest price at which it is legal to trade a good is a ( ) A. Production quota B. Price floor C. Price ceiling D. Tax ceiling 3. In Country J, it takes one hour to knit a pair of socks, and five hours to brew a gallon of cider. In Country K, it takes three hours to knit a pair of socks, and six hours to brew a gallon of cider. If trade were to open between the two countries, Ricardo would predict that ( ) A. Country J will export cider and Country K will export socks. B. Country J will export socks and Country K will export cider. C. Country J will export both socks and cider. D. Country K will export both socks and cider. 4. If Nation A can produce either 3x or 3y with one hour of labor, while nation B can produce either 1x or 1y with one hour of labor, and if labor is the only input, then ( ) A. Nation A has an absolute advantage in both goods. B. Nation B has an absolute advantage in both goods. C. Nation A has a comparative disadvantage in both goods. D. Nation A has a comparative advantage in both goods. 5. Mutually beneficial trade A. Allows both countries to consume a larger bundle of goods than before trade occurred.( ) B. Allows only the more productive country to consume a larger bundle of goods than before trade occurred. C. Allows only the less productive country to consume a larger bundle of goods than before trade occurred. D. Causes changes only in production, not consumption. 6. In the absence of trade, the consumption points available to a nation ( ) A. Are above the production possibility curve. B. Are on or inside the production possibility curve. C. Lie on the production possibility curve. D. Cannot be identified. 7. For Heckscher-Ohlin, the most important cause of the differences in relative commodity prices is the difference between countries in ( ) A. Factor endowments. B. National income. C. Technology. D. Tastes. 8. Country J has 1 million machines and 1 million workers, while country K has 2 million machines and 3 million workers. If computers are produced mostly by capital and beer is produced mostly by labor, the H-O model predicts that ( ) A. Country K will export computers in exchange for beer. B. Country J will export computers in exchange for beer. C. Country J is too small to be of economic interest to Country K. D. Computers and beer don’t mix, so trade cannot increase either country’s well-being. 9. Mexico is an unskilled labor abundant country, while the United States is a skilled labor abundant country. With the opening of trade, you would expect that, in the long run, wages for unskilled workers ( ) A. Decline in both countries. B. Decline in the United States and rise in Mexico. C. Rise in the United States and decline in Mexico. D. Rise in both countries 10. According to trade theory, if a nation has a comparative advantage in a capital-intensively produced good, and the rate of growth of capital is greater than the rate of growth of other inputs (e.g., labor), the pattern of growth which results will be ( ) A. Import replacing. B. Neutral as between capital intensive and other products. C. Export expanding. D. None of the above. 11. Arguments in favor of having developing countries focus on exporting manufactured goods include ( ) A. Strong support in industrialized countries for free trade in manufactured goods. B. Very low tariffs on manufactured textiles, apparel, and footwear in industrialized countries. C. Political preference for VERs among importing countries. D. A downward trend in the prices of primary products. 12. Which group definitely loses from international migration of labor? ( ) A. The migrants. B. The migrants’ new employers in the receiving country. C. The migrants’ old employers in the sending country. D. The migrants’ fellow workers who did not emigrate. 13. As technology advances, ( ) A. All opportunity cost decreases B. The PPF shift outward C. A country moves toward the midpoint along its PPF D. The PPF shift inward because unemployment occurs 14. If a country is operating at a point of production efficiency ( ) A. It enjoys growth when increasing production B. It produces on its production possibility frontier curve C. It must specialize in the production of a good D. It operates on its trade line 15. A cartel is ( ) A. Another name for a firm in an oligopoly B. A collusive agreement among a number of firms C. A government body that regulates an industry D. An antitrust law (Type and show your work) Practicum Question (25 points) Two countries, Haiti and the Dominican Republic, produce fruits and timber. Each island has a labor force of 1200 and the monthly productivity of each worker is as follow Basket of fruit Board feet of timber Haiti 10 5 Dominican Republic 30 10 a. Which county has an absolute advantage in the production of fruit? Timber? b. Which country has a comparative advantage in the production of fruit? Timber? c. Sketch the production possibility frontier (PPF) of both countries d. Both countries want to produce an equal amount of baskets of fruit and feet of timber. How should they allocate their workers to the two sectors? e. How can free trade move both countries beyond their respective PPF Extra credits (10 points) The demand and supply curves of the market for DVD at the local (US) market are as follow: P = 30 – Qd/2 and P= -1.5 + Qs/4 a. Find the equilibrium price and the equilibrium quantity when there is no international trade ( hint: solve for Qd and Qs And then make Qd=Qs to solve for Price and quantities) b. What are the equilibrium quantities when the nations trade freely at price of $15? Explain your rationale. c. How many units are exported? d. What is the resulting national gain? e. Do consumers and producers gain or lose from the free trade?
No expert has answered this question yet. You can browse … Read More...
Physics 2010 Sid Rudolph Fall 2009 MIDTERM 4 REVIEW Problems marked with an asterisk (*) are for the final. Solutions are on the course web page. 1. A. The drawing to the right shows glass tubing, a rubber bulb and two bottles. Is the situation you see possible? If so, carefully describe what has taken place in order to produce the situation depicted. B. The picture depicts three glass vessels, each filled with a liquid. The liquids each have different densities, and DA > DB > DC. In vessel B sits an unknown block halfway to the bottom and completely submerged. 1. _______ In which vessel would the block sit on the bottom? 2. _______ In which vessel would the block float on the top? 3. _______ In which vessel would the block feel the smallest buoyant force? 4. _______ In which vessels are buoyant forces on the block are the same? 5. _______ Assume the coefficient of volume expansion for the liquid in B and the block are $B > $block. If the temperature of vessel B with the block is raised, would block B rise to the surface, sink to the bottom, or remain where it is? 2. A circular tank with a 1.50 m radius is filled with two fluids, a 4.00 m layer of water and a 3.00 m layer of oil. Use Doil = 8.24 × 10 kg/m and Dwater = 1.00 × 10 kg/m , and Datm = 1.01 × 10 N/m . 2 3 3 3 5 2 A. What are the gauge and absolute pressures 1.00 m above the bottom of the tank? B. A block of material in the shape of a cube (m = 100 kg and side length = 42.0 cm) is released at the top of the oil layer. Where does the block come to rest? Justify your answer. If it comes to rest between two layers, specify which layers and what portion of the block sits in each layer. [Note: Vcube = a ]3 C. A small 1.00 cm radius opening is made in the side of the tank 0.500 m up from its base (block was removed). What volume of water drains from the tank in 10.0 s? (b) (a) 3. A tube is inserted into a vein in the wrist of a patient in a reclined position on a hospital bed. The heart is vertically 25.0 cm above the position of the wrist where the tube is inserted. Take DBLOOD = 1.06 × 103 kg/m3. The gauge venous blood pressure at the level of the heart is 6.16 × 103 N/m2. Assume blood behaves as an ideal nonviscous fluid. A. What is the gauge venous blood pressure at the position of the wrist? B. The tube coming from the wrist is connected to a bottle of whole blood the patient needs in a transfusion. See above figure (b). What is the minimum height above the level of the heart at which the bottle must be held to deliver the blood to the patient? C. Suppose the bottle of blood is held 1.00 m above the level of the heart. Assume the tube inserted in the wrist has a diameter of 2.80 mm. What is the velocity, v, and flow rate of blood as it enters the wrist. You may also assume the rate at which the blood level in the bottle drops is very small. The answer you get here is a substantial overstatement. Blood is not really a non-viscous fluid. 4. A 0.500 kg block is attached to a horizontal spring and oscillates back and forth on a frictionless surface with a frequency of f = 3.00 hz. The amplitude of this motion is 6.00 × 10 m. Assume to = 0 and is the instant the block is -2 at the equilibrium position moving to the left. A. Write expressions x(t) = !A sin (Tt) and v(t) = !AT cos (Tt) filling in the values of A and T. B. What is the total mechanical energy (METOT) of the block-spring system? C. Suppose the block, at the moment it reaches its maximum velocity to the left splits in half with only one of the halves remaining attached to the spring. What are the amplitude and frequency of the resulting oscillations? D. Suppose, instead of splitting at the position of maximum velocity to the left, the block now splits when it is at the extreme position in the left. What are the amplitude and frequency of the resulting motion? E. Describe in words what would happen to the period of oscillation if a second block identical to the first block were dropped on the first block at either of its extreme positions. 5. A. A spring has one end attached to a wall and the other end attached to two identical masses, mA and mB. The system is set into oscillation on a frictionless surface with amplitude A. See figure. When the system is momentarily at rest at x = -A whatever it is that holds mA to mB fails; and later in the motion mB moves away from mA to the right. 1. Location where the acceleration of mA is maximum and negative. 2. Location where the KE of mA is maximum. The next few questions ask you to compare the behavior of the mass-spring system after and before mB detached. Energy considerations are most useful here. 3. The amplitude of the mass-spring oscillation has (increased, decreased, not changed) after mB detaches. 4. The frequency of the mass-spring oscillation has (increased, decreased, stayed the same) after mB detaches. 5. The maximum speed of mA has (increased, decreased, stayed the same) after mB detaches. 6. The period of oscillation of the mass-spring system has (increased, decreased, stayed the same) after mB detaches. 7. The fraction of the total mechanical energy of the entire spring-2 mass system carried away with mB after mB detaches is B. A spherical object is completely immersed in a liquid and is neutrally buoyant some distance above the bottom of the vessel. See figure. The upper surface of the liquid is open to the earth’s atmosphere. 1. How is the density of the fluid related to the density of the spherical object? 2. Assume the fluid and object are incompressible. In addition, the $sphere (coefficient of volume expansion) > $liquid. For the following items below, indicate whether the object sinks to the bottom, rises to the surface, or does nothing based on the changes described. a. Atmospheric pressure drops by 20%. b. Salt is dissolved in the liquid in the same way fresh water is turned into salt water. c. The entire apparatus is warmed 10oC (liquid and object are both warmed). d. The entire apparatus is transported to the surface of the moon. (gmoon = 1.6 m/s , PATM = 0 on moon) 2 e. 100 cm3 of the liquid is removed from the top. The object is still initially submerged. 6. A. A mass m is attached to a spring and oscillating on a frictionless, horizontal surface. See figure. At the instant the mass passes the equilibrium position moving to the right, half the mass detaches from the other half. The oscillating system is now the spring and half the original mass with the detached mass moving off to the right with constant velocity. Relative to the original spring-mass system, the new spring-mass system with half the mass oscillates with … In the spaces provided below, enter the words larger, smaller or the same that best completes the above sentence.. 1. amplitude 2. period 3. frequency 4. maximum velocity 5. mechanical energy B. A solid cylinder is floating at the interface between water and oil with 3/4 of the cylinder in the water region and 1/4 of the cylinder in the oil region. See figure. Select the item in the parenthesis that best fits the statement. 1. The item (oil, water, and/or cylinder) with the largest density. 2. The item (oil, water, and/or cylinder) with the smallest density. 3. The weight of the cylinder (is equal to, greater than or less than) the total buoyant force it feels. 4. The density of the cylinder (is equal to, less than, or greater than) the density of water. rC. Three thermometers in different settings record temperatures T1 = 1000°F, T2 = 1000°C, and T3 = 1000 K. In the space below select T1, T2 or T3, that best fits the statement. 1. The thermometer in the hottest environment. 2. The thermometer in the coolest environment. 3. The thermometer reading a temperature 900° above the boiling point of water. 7. An oil tanker in the shape of a rectangular solid is filled with oil (Doil = 880 kg/m ). The flat bottom of the 3 hull is 48.0 m wide and sits 26.0 m below the surface of the surrounding water. Inside the hull the oil is stored to a depth of 24.0 m. The length of the tanker, assumed filled with oil along the entire length, is 280 m. View from Rear View from Side Note: Dsalt water = 1.015 × 10 kg/m ; Vrectangular solid = length × width × height. 3 3 A. At the bottom of the hull, what is the water pressure on the outside and the oil pressure on the inside of the horizontal bottom part of the hull? Assume the Po above the oil is the same as the Po above the water and its value is Po = 1.01 × 10 N/m . 5 2 B. If you did part A correctly you determined that the water pressure on the horizontal bottom part of the hull is larger than the oil pressure there. Explain why this MUST be the case. C. What buoyant force does the tanker feel? D. What is the weight of the tanker, excluding the weight of the oil in the hull? 8. A. Water is poured into a tall glass cylinder until it reaches a height of 24.0 cm above the bottom of the cylinder. Next, olive oil (Doil = 920 kg/m ) is very carefully added until the total amount of 3 fluid reaches 48.0 cm above the bottom of the cylinder. Olive oil and water do not mix. See figure. Take Dwater = 1.00 × 10 kg/m and Patm = 1.01 × 10 N/m . 3 3 5 2 1. Indicate on the drawing which layer is water and which is olive oil. 2. What is the gauge pressure 10.0 cm below the top of the upper fluid layer in the cylinder. 3. What is the gauge pressure on the bottom of the cylinder? 4. If the cylinder is in the shape of a right circular cylinder with radius of 3.60 cm, what force is exerted on the bottom of the cylinder? B. A 0.200 kg mass is hung from a massless spring. At equilibrium, the spring stretched 28.0 cm below its unstretched length. This mass is now replaced with a 0.500 kg mass. The 0.500 kg mass is lowered to the original equilibrium position of the 0.200 kg mass and suddenly released producing vertical SHM. 1. What is the spring constant for this spring? 2. What is the period of oscillation for the 0.500 kg/spring system? 3. What is the amplitude of this oscillation? r9. The drawing shows a possible design for a thermostat. It consists of an aluminum rod whose length is 5.00 cm at 20.0°C. The thermostat switches an air conditioner when the end of the rod just touches the contact. The position of the contact can be changed with an adjustment screw. What is the size of the spacing such that the air conditioner turns on at 27.0°C. This is not a very practical device. Take “al = 2.3 × 10 /°C. -5 r10. The following is an effective technique for determining the temperature TF inside a furnace. Inside the furnace is 100 gm of molten (i.e., in a liquid state) lead (Pb). The lead is dropped into an aluminum calorimeter containing 200 gm water both at an initial temperature of 10.0°C. After equilibrium is reached, the temperature reads 21.8°C. Assumptions: (1) No water is vaporized; (2) no heat is lost to or gained from the environment; and (3) the specific heat for the lead is the same whether the lead is a solid or a liquid. DATA TABLE LEAD CALORIMETER WATER mPb = 100 gm mAl = 150 gm mW = 200 gm CPb = 0.0305 cal/gm°C CAl = 0.215 cal/gm°C CW = 1.0 cal/gm°C LF = 6.0 ca./gm (heat of fusion) Tinit = 10.0°C Tinit = 10.0°C MPPb = 327°C (melting point) TF = unknown Tequilibrium = 21.8°C A. In words, describe the distinct steps in the cooling of lead. B. How many calories of heat are absorbed by the calorimeter and the water it contains to reach 21.8°C? C. How many calories are lost by the lead in cooling from TF to the final equilibrium temperature of 21.8°C? D. What was the original furnace temperature? E. If the same amount of aluminum (CAl = 0.215 cal/gm°C and LM = 21.5 cal/gm) were used in the same furnace instead of lead, would the final equilibrium temperature be higher, less or the same as in the lead case? No calculation is needed to answer this. Please explain. r11. The length of aluminum cable between consecutive support towers carrying electricity to a large metropolitan area is 180.00 m on a hot August day when the temperature is 38°C. Use “(Al) = 24 × 10-6/°C. A. What is the length of the same section of aluminum cable on a very cold winter day when T = -24°C? B. If the same length of copper (” = 17 × 10-6/°C) cable (i.e., 180.00 m on the same hot August day) were used instead of aluminum, would the length of the copper cable be shorter, longer or the same as that of the aluminum on the same winter day as in (A)? Please explain your conclusion You do not have to do any calculations here. r12. You wish to make a cup of coffee with cream in a 0.250 kg mug (cmug = 900 J/kg°C) with 0.325 kg coffee (ccoffee = 4.18 × 10 J/kg°C) starting at 25.0°C and 0.010 kg cream (ccream = 3.80 × 10 J/kg°C) at 10.0°C. 3 3 You use a 50.0 W electric heater to bring the coffee, cream and mug to a final temperature of 90.0°C. How long must the coffee system be heated? Indicate clearly the assumptions you need to make. r13. A 75.0 kg patient is running a fever of 106°F and is given an alcohol rubdown to lower his body temperature. Take the specific heat of the human body to be Cbody = 3.48 × 10 J/kg°C, the heat of 3 evaporation of the rubbing alcohol to be Lv(alcohol) = 8.51 × 10 J/kg, and the density of the rubbing 5 alcohol to be 793 kg/m3. You may assume that all the heat removed from the fevered body goes into evaporating the alcohol, and that while the patient’s body is cooling, his metabolism adds no measurable heat. A. What quantity of heat must be removed from the body to lower its temperature to 99.0°F? B. What volume of rubbing alcohol is required? C. This is a qualitative question. Give an answer and explanation. Suppose you were told that the alcohol applied started at room temperature (. 70°F) and were given the specific heat for the alcohol. Thus, you now expect some of the body heat warming the alcohol to the temperature of the fever before evaporation occurs. How would this effect the result of the calculation in part (B)? r14. A 56.0 kg hypothermia victim is running a body temperature of 91.0°F. The victim is far away from any immediate medical treatment. Her friends decide to treat the hypothermia victim by placing the victim in a sleeping bag with one of her friends and use the heat from the friend to raise the victim’s body temperature. Take the specific heat of the human body to be Cbody = 3.48 × 10 J/kg°C. Assume that the sleeping bag acts 3 like a perfect calorimeter and also assume no heat is lost to or obtained from the sleeping bag. Finally, assume all the heat that warms the hypothermia victim comes from the basic metabolic heat produced by the body of the victim’s friend in the sleeping bag with her and that metabolism is rated at 2.00 × 106 cal/day, and that the victim’s metabolism is negligible. A. How much heat must be added to the victim’s body to get her temperature up to 98.0°F? B. How long must the victim remain in the sleeping bag with her friend to achieve this temperature change? C. This is a qualitative question. If the thermal characteristics of the sleeping bag are now taken into account, but still assuming no heat leaves or enters the sleeping bag, how will the answer to question (b) above be different? r15. A few years back a lawsuit was filed by a woman against McDonald’s because she scalded herself with a Styrofoam cup filled with coffee which she spilled on herself while driving. This question was spawned by that incredible legal action and represents a possible action taken by McDonald’s to insure cooler coffee. Suppose a typical cup of coffee sold by McDonald’s is basically 400 ml of hot water and when poured into the Styrofoam cup its temperature is 96.0°C. Take 1.00 ml to have a mass of 1.00 gm and = 4.19 kJ/kg°C. Neglect any heat lost to the cup and assume no heat is lost by the coffee to the environment. A. How much heat in joules must the coffee lose to bring its temperature to a drinkable 68.0°C? B. McDonald’s possible approach to lowering the temperature of the 96.0°C coffee to 68.0°C is to add a cube of ice initially at 0.0°C. (Take Lf = 334 kJ/kg.) What mass of ice has to be added to the coffee to reduce its initial temperature to the desired 68.0°C? r16. During this past Thanksgiving your instructor overdid it and consumed 3000 Cal of food and dessert. Remember 1.0 Cal = 4.19 x 10 J. For the questions below, as 3 sume no heat is lost to the environment. [Note: = 33.5 x 105 J/kg; = 4.19 x 103 J/kgoC] A. If all of this energy went into heating 65.0 kg water starting at 37.0oC (a mass approximately that of your instructor), what would be the final temperature of this water? B. Assume your instructor removes these overeating calories by running 10 kilometer races [note: 1.61 km = 1.00 mile]. Using the rule of thumb that 1 mile of jogging will require 100 Cal, what is the minimum number of races your instructor must run to consume the 3000 Cal in part A as exercise? C. The year before, your instructor was particularly gluttonous and consumed 5000 Cal. Assuming the same conditions of water mass (65.0 kg) and starting temperature (37.0oC) as in A, what is the final temperature of the water system, and if any water vaporizes to steam, how much? [Note: BP(H2O) = 100 C] o 17. Below is the position vs. time graph for the simple harmonic of a spring oscillation on a frictionless horizontal surface. Motion to the right is positive. 1. The earliest instant of time, including t0 = 0 at which the PEelastic is maximum. 2. The earliest instant of time at which the KE of the mass is a maximum and the mass is moving to the right. 3. The earliest instant of time at which the acceleration of the mass is maximum and positive. 4. The earliest instant of time at which the speed of the mass is zero. 18. A. A spring is attached to a post at the top of a 15.0° frictionless ramp. A 2.00 kg mass is attached to the spring and the mass is slowly allowed to stretch the spring to the equilibrium position of the mass-spring system, the spring stretches by 0.400 m See figure. The mass is now pulled an additional 10.0 cm and released. The mass-spring system executes simple harmonic motion. 1. What is the spring constant, k, of the spring. 2. What are the amplitude and period of oscillation of the mass-spring system? B. A solid, uniform cylinder is floating at the interface between water (Dwater = 1.00 × 103 kg/m ) and oil (Doil = 8.24 × 10 kg/m ) with 3/4 of the cylinder in the water region and 3 3 3 1/4 of the cylinder in the oil region. Assume the axis of the cylinder is perfectly vertical. See figure. 1. What is the density of the material out of which the cylinder is made? 2. Assume the upper surface of the oil region si open to the atmosphere (Datm = 1.01 × 10 N/m ) and the oil-water interface is 0.500 m below the 5 2 upper surface of the oil. Also assume the height of the cylinder is 10.0 cm. What is the gauge pressure on the bottom surface of the cylinder? Recall: Pgauge = P – PATM. 19. A. A mass m is attached to a spring and is oscillating on a frictionless horizontal surface (see figure). At the instant the mass is at an amplitude position a second identical mass is carefully placed on top of the original mass. The oscillating system is now the spring and the two identical masses. Relative to the original spring-single mass system, the new spring-2-mass system oscillates with a … In the spaces provided below, enter (I) for increased, (D) for decreased, or (R) remains unchanged, that best completes the above last sentence. 1. amplitude. 2. period. 3. frequency. 4. spring constant. 5. maximum speed. 6. mechanical energy. 7. maximum acceleration. B. Suppose you are asked about the absolute pressure at some depth h below the surface of a liquid. The top surface is exposed to the atmosphere on a sunny day in Salt Lake City. For each statement below in the spaces provided, enter I for increase, D for decrease, or R for remains the same, when accounting for what happens to the absolute pressure at the point you are observing. 1. More liquid is added so now the observation point is farther below the surface. 2. The fluid is now exchanged for a less dense fluid. The observation point is at same h. 3. The experiment is moved to New York City, which is at sea level, on a sunny day. 4. The fluid is now seen to be moving with some speed v past the observation point. 5. The observation point is moved closer to the surface of the liquid. 6. The air above the fluid is removed by a vacuum system. 7. The apparatus is moved to a laboratory on the surface of the moon. 20. A 3.00 kg mass is attached to a spring (k = 52.0 N/m) that is hanging vertically from a fixed support. The mass is moved to a position 0.800 m lower than the unstretched position of the end of the spring. The spring is then released and the mass-spring system executes SHM. Take the 0.800 m of the mass as the reference location for its gravitational PE. A. What is the equilibrium position of the mass-spring system? B. What is the amplitude of the SHM the mass-spring system executes? C. What is the period of the oscillation of this system? D. What is the total mechanical energy of the mass-spring system at the moment the mass is released? E. What are (i) the KE of the mass and (ii) the speed of the mass when the spring is at its equilibrium position? 21. A 38.0 kg block is moving back and forth on a frictionless horizontal surface between two springs. The spring on the right has a force constant kR = 2.50 × 10 N/m. When the block is between the two 3 springs its speed (v) is 1.82 m/s. See figure. A. If the block compresses the left spring to 5.62 cm beyond its uncompressed length, determine the value of kL. B. What is the maximum compression of the right spring when the mass interacts with it? C. What is the total time the spring on the right is compressed during a single event? 22. Two identical containers are connected at the bottom via a tube of negligible volume and a valve which is closed. Both containers are filled initially to the same height of 1.00 m, one with chloroform (DC = 1530 kg/m ) in the left chamber and the other 3 with mercury in the right chamber (DHg = 1.36 × 10 kg/m ). 4 3 Sitting on top of each identical circular container is a massless plate that can slide up or down without friction and without allowing any fluid to leak past. The radius of the circular plate is 12.0 cm. The valve is now opened. A. What volume of mercury drains into the chloroform container? (Note: Vcyl = Br h) 2 B. What mass must be placed on the plate on the chloroform side to force all the mercury, but none of the chloroform, back to the mercury chamber? 23. A 12.0 kg mass M is attached to a cord that is wrapped around a wheel in the shape of a uniform disk of radius r = 12.0 cm and mass m = 10.0 kg. The block starts from rest and accelerates down the frictionless incline with constant acceleration. Assume the disk axle is frictionless. Note: Idisk = 1/2 mr . 2 A. Use energy methods to find the velocity of the block after it has moved 2.00 m down the incline. B. What is the constant acceleration of the block and the angular acceleration of the wheel? C. How many revolutions does the wheel turn for the distance the block travels in (A)? D. If the uniform disk were replaced by a uniform sphere with the same r and m of the disk, would the acceleration of the block attached to the sphere be larger, smaller, or the same as that for the block attached to the disk? Note: Isphere = 2/5 mr . 2 24. A pulley is in the shape of a uniform disk of mass m = 5.00 kg and radius r = 6.40 cm. The pulley can rotate without friction about an axis through the center of mass. A massless cord is wrapped around the pulley and connected to a 1.80 kg mass. The 1.80 kg mass is released from rest and falls 1.50 m. See figure. Note: Idisk = 1/2 mr . 2 A. Use energy methods to determine the speed of the block after falling 1.50 m. B. What is the constant acceleration of the block and the angular acceleration of the wheel? C. How many revolutions does the pulley disk turn for the distance the block travels in (A)? D Suppose the disk were replaced by a uniform sphere with the same r and m of the disk. Would the acceleration of the block attached to the sphere be larger, smaller, or the same as that for the block attached to the the disk? Note: Isphere 2/5 mr . 2 26. A 700.0 N fisherman is walking toward the edge of a 200 N plank as shown. He has placed a can of worms weighing 75.0 N on the left side of the plank as indicated in the drawing. The plank is the horizontal section in the drawing. A. Identify all the forces the plank feels before it begins to tip. Draw a free body diagram. B. As the fisherman nears the point on the plank where it begins to tip, how do the upward forces the supports exert on the plank change. C. How far a distance, as measured from the center of the right support, can he walk before the plank begins to tip? 26. A 75.0 kg sign hangs from a 4.80 m uniform horizontal rod whose mass is 120 kg. The rod is supported by a cable that makes an angle of 53° with the rod. he sign hangs 3.60 m out along the rod. A. What is the tension in the cable? B. What are the forces PPv and PPH exerted by the wall on the left end of the rod? 27. A 1.00 × 104 N great white shark is hanging by a cable attached to a 4.00 m massless rod that can pivot at its base. See figure. A. Determine the tension in the cable supporting the upper end of the rod. See figure. B. Determine the force (a vector quantity) exerted on the base of the rod. Suggestion: Find this force by first evaluating the separate components of the force. See figure. 28. A 6.00 m uniform beam extends horizontally from a hinge fixed on a wall on the left. A cable is attached to the right end of the beam. The cable makes an angle of 30.0° with respect to the horizontal and the right end of the cable is fixed to a wall on the right. At the right end of the cable hangs a 140.0 kg mass. The mass of the beam is 240.0 kg. See figure. A. Find the tension in the cable. B. Find the vertical and horizontal forces the hinge exerts on the left end of the beam. 29 A. The blades of a “Cuisinart” blender when run at the “mix” level, start from rest and reach 2.00 × 103 rpm (revolutions per minute) in 1.60 s. The edges of the blades are 3.10 cm from the center of the circle about which they rotate. 1. What is the angular acceleration of the blades in rad/s2 while they are accelerating? 2. Through how many rotations did the blades travel in that 1.60 s? 3. If the blades have a moment of inertia of 5.00 × 10-5 kg m2, what net torque did the blades feel while accelerating? B. A 7.50 × 10 N 4 shipping crate is hanging by a cable attached to a uniform 1.20 × 104 N steel beam that can pivot at its base. A second cable supports the beam and is attached to a wall. See figure. 1. Determine the tension T in the upper cable. 2. Determine the magnitude of the force exerted on the beam at its base. See drawing. 30. The drawing shows a uniform ladder of length L and weight 220 N. The ladder is sitting at an angle of 30° above the horizontal resting on the corner of a concrete wall at a point that is one-fourth of the way from the end of the ladder. A 640 N construction worker is standing on the ladder one-third of the way up from the end of the ladder which is resting on the ground. Assume the corner of the wall on which the ladder rests exerts only a normal force on the ladder at the point where there is contact. A. What is the magnitude of the normal force the wall exerts on the ladder? B. Find the magnitude of both the normal force the ground exerts on the left end of the ladder and the static frictional force the ground exerts on the left end of the ladder. 31. A. A solid, right circular cylinder (radius = 0.150 m, height = 0.120 m) has a mass m. The cylinder is floating in a tank in the interface between two liquids that do not mix: water on the bottom and oil above. One-third of the cylinder is in the oil layer (Doil = 725 kg/m ) 3 and two-thirds in the water layer (Dwater = 1.00 × 10 kg/m ). See 3 3 drawing. Note: V(circular cylinder) = B r2 h. 1. Find the mass of the cylinder. 2. With the cylinder present, take the thickness of the oil layer to be 0.200 m and the thickness of the water layer to be 0.300 m. What is the gauge pressure at the bottom of the tank? Assume the top of the oil layer is exposed to the atmosphere. B. A block rests on a frictionless horizontal surface and is attached to a spring. When set into simple harmonic motion, the block oscillates back and forth with an angular frequency of T = 7.52 rad/s. The drawing indicates the position of the block when the spring is unstretched. That position is labeled “x = 0 m” in the drawing. The drawing also shows a small bottle whose left edge is located at Xb = 0.0900 m. The block is now pulled to the right, stretching the spring by Xs = 0.0343 m, and is then thrown to the left, i.e., given an initial push to the left. In order for the block to knock over the bottle when it is moving to the right, it must be “thrown” with an initial speed to the left v0. Ignoring the width of the block, what is the minimum value of v0? 32. B. Three objects, a disk (ICM = ½ MR ), a hoop (ICM = MR ), and a hollow ball (ICM = b MR ) all have 2 2 2 the same mass and radius. Each is subject to the same uniform tangential force that causes the object, starting from rest, to rotate with increasing angular speed about an axis through the center of mass for each object. In the case of the hollow ball the tangential force has a moment arm equal to the radius of the ball. In the space below, enter D for disk, H for hoop, and/or B for hollow ball, or same to best answer the question. 1. The object with the largest moment of inertia about the axis through the CM. 2. The object experiencing the greatest net torque. 3. The object with the greatest angular acceleration during the period the force is acting. 4. The object rotating with the smallest angular speed assuming the force has been acting for the same length of time on each object. 33. A. A uniform disk (D), hoop (H), and sphere (S), all with the same mass and radius, can freely rotate about an axis through the center of mass (CM) of each. A massless string is wrapped around each item. The string is used to apply a constant and equal tangential force to each object. See figure. For the statements below, enter D, H, S, none or the same. Assume all objects start from rest at the same instant. 1. The one with the smallest moment of inertia about the shown axis. 2. The object experiencing the largest net torque. 3. The object undergoing the smallest angular acceleration. 4. The object with the largest angular speed after an elapsed time of 5.0 s. 5. The object for which the largest amount of string has unraveled in 5.0 s. 6. The object with the smallest KErot after 5.0 s. 7. The object that undergoes the most rotations in 5.0 s. B. A spherical object is completely immersed in a liquid of density Dliq some distance above the bottom of the vessel. See figure. The upper surface is initially open to the earth’s atmosphere at sea level. Assume the liquid and object are both incompressible. For the items below, indicate whether the object sinks to the bottom (B), rises to the surface (T), or does nothing (N). 1. The vessel is brought to Salt Lake City. 2. Salt is dissolved in the liquid in the same way fresh water is turned into salt water. 3. The top 50 cm3 of the liquid is removed from the vessel. 4. The entire apparatus is transported to the surface of the moon. 5. The volume of the spherical object is increased by heating it without heating the liquid. 6. The spherical object is moved 10 cm farther down in the vessel and released. 7. A mass is placed on the top surface of the liquid in the vessel increasing the pressure at the surface. No fluid leaks. 34. A 2.20 × 103 N uniform beam is attached to an overhead beam as shown in the drawing. A 3.60 × 103 N trunk hangs from an attachment to the beam two-thirds of the way down from the upper connection of the beam to the overhead support. A cable is tied to the lower end of the beam and is also attached to the wall on the right. A. What is the tension in the cable connecting the lower end of the beam to the wall? B. What are magnitude of the vertical and horizontal components of the force the overhead beam exerts on the upper end of the beam at P? 35. A. A 12.0 kg block moves back and forth on a frictionless horizontal surface between two springs. The spring on the right has a force constant k = 825 N/m. When the block arrives at the spring on the right, it compresses that spring 0.180 m from its unstretched position. 1. What is the total mechanical energy of the block and two spring system? 2. With what speed does the block travel between the two springs while not in contact with either spring? 3. Suppose the block, after arriving at the left spring, remains in contact with that spring for a total time of 0.650 s, before separating on its way to the right spring? Using the connection between this 0.650 s and the period of oscillation between the block and the left spring, determine the spring constant of the left spring. B. A turkey baster (see figure) consists of a squeeze bulb attached to a plastic tube. When the bulb is squeezed and released, with the open end of the tube under the surface of the turkey gravy, the gravy rises in the tube to a distance h, as shown in the drawing. It can then be squirted over the turkey. Using Patm = 1.013 × 105 N/m2 for atmospheric pressure and 1.10 × 103 kg/m3 for the density of the gravy, determine the absolute pressure of the air in the bulb with the distance h = 0.160 m. Give answer to three significant digits. 36. A. The pictures below depict three glass vessels, each filled with a liquid. The liquids each have different densities, and DA > DB > DC. In vessel C an unknown block is neutrally buoyant halfway to the bottom and completely submerged. A, B, and/or C, or none are all possible answers. 1. _______ In which vessel(s) would the block sink all the way to the bottom? 2. _______ In which vessel(s) would the largest volume of the block be exposed above the surface of the liquid? 3. _______ In which vessel(s) would the buoyant forces on the block be the same? B. A swinging pendulum (A) and a mass-spring system (B) are built to have identical periods. For the statements below enter either A, B, U (unchanged) to best fit which oscillating system would have the larger period as a result of the change. 1. _______ The mass of the mass-spring system is increased. 2. _______ The mass of the swinging pendulum is increased without altering the location of its center of mass. 3. _______ The spring constant of the mass-spring system is increased. 4. _______ The length of the swinging pendulum system is increased. 5. _______ Both systems are taken to the moon and set oscillating. C. A block of mass m moves back and forth on a frictionless surface between two springs. See drawing. Assume kL > kR. For the statements below enter L for the left spring, R for the right spring, or same as the case may be. 1. _______ The spring that has the maximum compression when m is momentarily at rest. 2. _______ The spring that stores the larger elastic potential energy when maximally compressed. 3. _______ The spring that momentarily stops the block in the least time once the block arrives at the spring. 37. A uniform beam extending at right angles from a wall is used to display an advertising sign for an eatery. The beam is 2.50 m long an weighs 80.0 N. The sign, whose dimensions are 1.00 m by 0.800 m, is uniform, and weighs 200. N, hangs from the beam as shown in the drawing. A cable, attached to the wall of the eatery at a point on the beam where the inside end of the sign is attached to the beam and making an angle of 60.0° with the beam, supports this advertising structure. A. What is the magnitude of the tension in the cable supporting the beam? B. What are the magnitudes of the horizontal and vertical forces the wall exerts on the left end of the beam? 38. A. Examine the picture shown to the right. Initially, before the pump is turned on, the two masses (m1 = 1.00 kg, m2 = 2.75 kg) are held in place. the pressures above and below m1 are Patm = 1.01 × 10 N/m and 5 2 the spring is in its unstretched position. The pump is turned on and the masses are allowed to move. The mass m1 moves without friction inside a cylindrical piston of radius r = 3.85 cm. Once equilibrium is established, by what distance has the spring stretched? Take k = 2.00 × 103 N/m for the spring constant. B. A solid cylinder (radius 0.125 m and height 0.150 m) has a mass of 6.50 kg. The cylinder is floating in water. Oil (Doil = 725 kg/m ) is poured on top of the water until 3 the situation shown in the drawing results. How much of the height (in meters) of the cylinder remains in the water layer?