Please write clearly, show all work in an organized fashion, and circle answers. 1) Estimate the weight savings if a typical automobile engine (100 kg) is made of aluminum instead of cast iron. Assume the total volume required is the same. (The density of iron is 7.86 g/cm3, the density of aluminum is 2.70 g/cm3). Hint: density = mass/volume 2) For question 1, explain the changes in performance of the automobile in terms of : a) acceleration (faster, same, slower) b) braking (faster, same, slower) – remember braking involves friction of car’s wheels with the road c) handling under high winds (better, same, worse) Hint: think in terms of freshman physics (F=ma, and frictional force depends on the load applied) 3) For question 1, estimate the change in cost if the cast iron were replaced with aluminum. Aluminum costs about $2./kg, and mild steel costs about $0.4/kg. Take into account the lower mass of the aluminum engine. 4) Determine the bonding type between the following types of atoms: Al-Ni, Si-Ge, C-O, Fe-O, Ne-Ar 5)Explain why a Ti atom is larger than a Cu atom.
The combustion of propane 3 8 (C H ) in the presence of excess oxygen yields 2 CO and 2 H O : 3 8 2 2 2 C H (g) + 5O (g)®3CO (g) + 4H O (g) When 2.5 mol of 2 O are consumed in their reaction, __________ mol of 2 CO are produced. A) 1.5 B) 3.0 C) 5.0 D) 6.0 E) 2.5
From a biological standpoint, a legal abortion performed in an accredited facility, by a skilled practitioner, and done before the16th week of pregnancy is Question 3 options: extremely risky safer than continuing the pregnancy and delivering the child used by many women as a primary method of contraception none of these choices is correct
From a biological standpoint, a legal abortion performed in an … Read More...
two current carrying wires . wire # 1carries a current I into the page . wire #2 carries a current I eighter into or out of page. If the net magnetic field at point A to the left . 1) I is in and I>I, 2) I is out and I>I, 3) I is in and I<I, 4) I is out and I<I, 5) I=I
PHY-102: Energy and Circular Motion Exercises Complete the following exercises. 1. A rifle with a longer barrel can fire bullets with a larger velocity than a rifle with a shorter barrel. a. Explain this using the impulse-momentum theorem. b. Explain this using the work-energy theorem 2. Use physics terms to explain the benefits of crumple zones in modern cars. 3. When a gun is fired at the shooting range, the gun recoils (moves backward). Explain this using the law of conservation of momentum. 4. Rank the following in terms of increasing inertia: A. A 10,000 kg train car at rest B. A 100 kg person running at 5 m/s C. A 1200 kg car going 15 m/s D. A 15 kg meteor going at a speed of 1000 m/s 5. Rank the following in terms of increasing momentum: A. A 10,000 kg train car at rest B. A 100 kg person running at 5 m/s C. A 1200 kg car going 15 m/s D. A 15 kg meteor going at a speed of 1000 m/s 6. Rank the following in terms of increasing kinetic energy: A. A 1200 kg car going 15 m/s B. A 10,000 kg train car at rest C. A 15 kg meteor going at a speed of 1000 m/s D. A 100 kg person running at 5 m/s 7. Ben (55 kg) is standing on very slippery ice when Junior (25 kg) bumps into him. Junior was moving at a speed of 8 m/s before the collision and Ben and Junior embrace after the collision. Find the speed of Ben and Junior as they move across the ice after the collision. Give the answer in m/s. Describe the work you did to get the answer. 8. Identical marbles are released from the same height on each of the following four frictionless ramps. Compare the speed of the marbles at the end of each ramp. Explain your reasoning. 9. A force of only 150 N can lift a 600 N sack of flour to a height of 0.50 m when using a lever as shown in the diagram below. a. Find the work done on the sack of flour (in J). b. Find the distance you must push with the 150 N force on the left side (in m). c. Briefly explain the benefit of using a lever to lift a heavy object. 10. Rank the following in terms of increasing power. A. Doing 100 J of work in 10 seconds. B. Doing 100 J of work in 5 seconds. C. Doing 200 J of work in 5 seconds. D. Doing 400 J of work in 30 seconds. 11. A student lifts a 25 kg mass a vertical distance of 1.6 m in a time of 2.0 seconds. a. Find the force needed to lift the mass (in N). b. Find the work done by the student (in J). c. Find the power exerted by the student (in W). 12. A satellite is put into an orbit at a distance from the center of the Earth equal to twice the distance from the center of the Earth to the surface. If the satellite had a weight at the surface of 4000 N, what is the force of gravity (weight) of the satellite when it is in its orbit? Give your answer in newtons, N. 13. Consider a satellite in a circular orbit around the Earth. a. Why is it important to give a satellite a horizontal speed when placing it in orbit? b. What will happen if the horizontal speed is too small? c. What will happen if the horizontal speed is too large? 14. If you drop an object from a distance of 1 meter above the ground, where would it fall to the ground in the shortest time: Atop Mt. Everest or in New York? 15. Why do the astronauts aboard the space station appear to be weightless? 16. Why do the passengers on a high-flying airplane not appear weightless, similar to the astronauts on the space station? 17. A ranger needs to capture a monkey hanging on a tree branch. The ranger aims his dart gun directly at the monkey and fires the tranquilizer dart. However, the monkey lets go of the branch at exactly the same time as the ranger fires the dart. Will the monkey get hit or will it avoid the dart? The remaining questions are multiple-choice questions: 18. Compared to its weight on Earth, a 5 kg object on the moon will weigh A. the same amount. B. less. C. more. 19. Compared to its mass on Earth, a 5 kg object on the moon will have A. the same mass. B. less mass. C. more mass. 20. The reason padded dashboards are used in cars is that they A. look nice and feel good. B. decrease the impulse in a collision. C. increase the force of impact in a collision. D. decrease the momentum of a collision. E. increase the time of impact in a collision. 21. Suppose you are standing on a frozen lake where there is no friction between your feet and the ice. What can you do to get off the lake? A. Bend over touching the ice in front of you and then bring you feet to your hands. B. Walk very slowly on tiptoe. C. Get on your hands and knees and crawl off the ice. D. Throw something in the direction opposite to the way you want to go. 22. A car travels in a circle with constant speed. Which of the following is true? A. The net force on the car is zero because the car is not accelerating. B. The net force on the car is directed forward, in the direction of travel. C. The net force on the car is directed inward, toward the center of the curve. D. The net force on the car is directed outward, away from the center of the curve. 23. A job is done slowly, and an identical job is done quickly. Which of the following is true? a. They require the same amount of force, but different amounts of work. b. They require the same amount of work, but different amounts of power. c. They require the same amounts of power, but different amounts of work. d. They require the same amounts of work, but different amounts of energy. 24. How many joules of work are done on a box when a force of 60 N pushes it 5 m in 3 seconds? a. 300 J b. 12 J c. 100 J d. 36 J e. 4 J 25. A 1 kg cart moving with a speed of 3 m/s collides with a 2 kg cart at rest. If the carts stick together after the collision, with what speed will they move after the collision? a. 3 m/s b. 1.5 m/s c. 1 m/s d. 2 m/s
Questions from Ishmael, Part 1 Type your answers to the following questions: 1. How do animals typically react to life in a zoo, according to Ishmael? And how, as a young gorilla, did zoo life affect him personally? 2. What does Ishmael mean by “Takers” and “Leavers?” Do these terms have any connotations to you (and if so, describe them), or do you see them as neutral? 3. Describe our culture’s origin myth, according to Ishmael. 4. After the events described in our culture’s origin myth, what was the next major event in human history that is essential in describing “how things came to be this way.” In the book it’s called “the middle of the story.” Describe this event, detailing what it meant for humankind. 5. According to Ishmael, how do Takers envision the role of humans “in the divine scheme?” What is humankind’s purpose? How has this perspective affected human/nature relationships? 6. According to Ishmael, how do most Takers envision the future of humanity? As part of your answer, describe how most Takers say we should deal with problems such as energy shortages and pollution. 7. What is Daniel Quinn trying to get you to perceive about the state of our culture’s relationship with nature? How does his story-telling approach affect your perception about environmental issues? To what extent is his approach successful, and why?
2. (10 points). An inventor claimed to have developed a power cycle having a thermal efficiency of 50%, while operating between hot and cold reservoirs at temperature TH and TC =250K. respectively where (a) TH=600K (b) TH=500K (c) TH=400K. Evaluate the claim in each of the three cases by answering (A) Possible and the cycle operates reversibly (B) Possible but the cycle operates only reversibly and not realistically operated, thus the claim is unlikely. (C) Impossible. Answer with 1, 2, or 3:
Capital Punishment For this paper, please read both the Ernest Van den Haag article and the Larry Tifft article. PICK A SIDE, either pro-capital punishment (death penalty) or abolitionist (anti-death penalty). This IS an ARGUMENTATIVE PAPER!!!!!!!!!!!! Using both the articles, your text book, (and a general source if you wish such as the Bible or dictionary), argue for your stance. You may also use the Marx/Durkheim handouts if you so wish, so long as there are SOCIOLOGY TERMS in your paper! You must: 1. Provide three points to back up your argument and include them in your thesis paragraph and explain them in the body of the paper; 2. Give voice to the opposing side. If you’re abolitionist, bring up any validity to Van den Haag, if you’re pro-capital punishment, bring up any validity to Tifft’s argument. 3. Use both a thesis opening paragraph and a solid conclusion paragraph. 4. Use SOCIOLOGY TERMS! 5. NO PERSONAL PRONOUNS! TECH requirements: • 12 point, Arial or Times Roman Numeral font. • 3 page long NOT including cover sheet and references page • Double spaced
EBIO/ECHM 100 – Homework #6 2015 Due Thursday October 8, 2015 1. Flow rates – in most bio- or chemical engineering problems, you will be working with flow rates rather than a singular amount of mass, moles or volume. When working with gases, a molar flow rate (mol/time) or a volumetric flow rate (volume/time) can be used in the ideal gas law. Consider a mixed gas consisting of 60% Hydrogen, 20% Nitrogen and 20% Carbon Monoxide (CO) which has a molar flow rate of 175 lbmol/min. The temperature is 200oF and pressure is 3 atm gauge. a. Calculate the individual molar flow rates of each component (mol/min) b. Calculate the total volumetric flow rate in ft3/min c. Determine the molar density of the mixed gas (mol/ft3) d. Determine the mass flow rate of the gas (g/min) e. Determine the mass fraction of hydrogen in the gas Read Section 6.5 of your textbook and/or watch the mini-lecture on statistics. That information will help you complete problems 2-4 In previous years, students in EBIO/ECHM 100 would test their ability to brew a repeatable batch of coffee. Let’s say you tried your best to brew three identical batches of coffee – you ground your own beans and measured exactly how many grounds you added to the pot. You took three samples from each batch and measured the absorbance. Representative data for the absorbance readings is given below. Batch 1 Batch 2 Batch 3 Measurement 1 0.343 0.374 0.327 Measurement 2 0.342 0.372 0.327 Measurement 3 0.371 0.375 0.328 2. For each batch of coffee (data in a vertical column), calculate the mean and standard deviation of the absorbance measurement of the three measurements taken from each batch (batch 1 has 3 absorbance measurements of .343, 0.342 and 0.371). Show at least one hand calculation on engineering paper, but you can do the rest in Excel if you wish, using the functions for average, =average(), and standard deviation, =stdev(). For example if you put data from batch 1 in column B, cells B2, B3 and B4 you could tell Excel to compute the average of those numbers by entering the equation =average(B2,B3,B4) in a neighboring cell. An alternate to way compute the average would be to type =(B2+B3+B4)/3. While you get the same answer with both methods, the second method become more cumbersome as your number of samples goes up. 3. Now, calculate the mean and standard deviation for the combination of all nine samples. 4. Why is the standard deviation calculated in #3 greater than those calculated in #2? Discuss this question in terms of experimental factors that could lead to scatter in your data (think back to the steps of making coffee and try to come up with at least 3 factors – these can address sample to sample variations or batch to batch variations). Staple the spreadsheet to the rest of your HW if using Excel. Adjust numbers so they report correct significant figures.