F7.10 The flame spread rate through porous solids increases with concurrent wind velocity. decreases with concurrent wind velocity. is independent of concurrent wind velocity. F7.11 Surface tension accelerates opposed-flow flame spread over liquid fuels. True False F7.12 Opposed-flow flame spread rates over a solid surface are typically much smaller than 1 mm/s. around 1mm/s. much greater than 1 mm/s. F7.13 Upward flame spread rate over a vertical surface is typically between 10 and 1000 mm/s. True False F7.14 The Steiner tunnel test described in ASTM standard E 84 is used to assess the fire performance of interior finish materials based on lateral flame spread over a vertical sample. True False F8.1 Describe the triad of fire growth. F8.2 Liquid pool fires reach steady burning conditions within seconds after ignition. True False F8.3 The heat of gasification of liquid fuels is typically less than 1 kJ/g. between 1 and 3 kJ/g. greater than 3 kJ/g. F8.4 The heat flux from the flame to the surface of real burning objects can usually be determined with sufficient accuracy so that reasonable burning rate predictions can be made. True False F8.5 The mass burning flux generally associated with extinction is 0.5 g/m2s. 5 g/m2s. 50 g/m2s. F8.6 The mass burning flux of a liquid pool fire is a function of only the pool diameter. only the fuel type. pool diameter and fuel type. F8.7 The energy release rate of real objects can be measured in an oxygen bomb calorimeter. an oxygen consumption calorimeter. a room/corner test. F8.8 The peak energy release rate of typical domestic upholstered furniture can be as high as 3000 kW. True False F8.9 Draw a typical curve of the mass burning flux of a char forming fuel as a function of time. F8.10 A fast fire as defined in NFPA 72B grows proportionally to t2 and reaches an energy release rate of 1 MW in 75 sec. 150 sec. 300 sec. F9.1 Air entrainment into turbulent pool fire flames is due to buoyancy. True False F9.2 The frequency of vortex shedding in turbulent pool fire flames increases with pool diameter. decreases with pool diameter. is independent of pool diameter. F9.3 The height of turbulent jet flames for a given fuel type and orifice size is independent of energy release rate. True False F9.4 The exit velocities of fuel vapors leaving a solid or liquid pool fire surface are responsible for entrainment of air in the plume. True False F9.5 The height of a turbulent pool fire flame is a function of only energy release rate. only pool diameter. energy release rate and pool diameter. F9.6 Turbulent pool fire flame heights fluctuate in time within a factor of 2. True False F9.7 The Q* value for jet fires is 102 or greater. 104 or greater. 106 or greater. F9.8 The temperature in the continuous flame region of moderate size turbulent pool fires is approximately 820°C. True False F9.9 The temperature at the maximum flame height of a turbulent pool fire flame is approximately 1200°C. 800°C. 300°C. F9.10 The adiabatic flame temperature of hydrocarbon fuels is 1700-2000°C. 2000-2300°C. 2300-2600°C. F10.1 The stoichiometric air to fuel mass ratio of hydrocarbon fuels is of the order of 1.5 g/g. 15 g/g. 150 g/g. F10.2 Give two examples of products of incomplete combustion that occur in fires. F10.3 Slight amounts of products of incomplete combustion are generated in overventilated fires. True False F10.4 The CO yield of a fire is a function of only the fuel involved. only the ventilation conditions. the fuel and the ventilation conditions. F10.5 A carboxyhemoglobin level of 40% in the blood is usually lethal. True (doubt) False F10.6 Carbon monoxide is the leading killer of people in fires. True False F10.7 HCN is a narcotic gas. an irritant gas. a fuel vapor. F10.8 The hazard to humans from narcotic gases is a function of only the concentration of the gas. only the duration of exposure. the product of concentration and duration of exposure. F10.9 The effects on lethality of CO, HCN, and reduced O2 are additive. True False F10.10 Irritant gases typically cause post-exposure fatalities. True False F10.11 Visibility through smoke improves with increasing optical density. True False F10.12 Heat stress occurs when the skin is exposed to a heat flux of 1 kW/m2. the skin reaches a temperature of 45°C. the body’s core temperature reaches 41°C.

F7.10 The flame spread rate through porous solids increases with concurrent wind velocity. decreases with concurrent wind velocity. is independent of concurrent wind velocity. F7.11 Surface tension accelerates opposed-flow flame spread over liquid fuels. True False F7.12 Opposed-flow flame spread rates over a solid surface are typically much smaller than 1 mm/s. around 1mm/s. much greater than 1 mm/s. F7.13 Upward flame spread rate over a vertical surface is typically between 10 and 1000 mm/s. True False F7.14 The Steiner tunnel test described in ASTM standard E 84 is used to assess the fire performance of interior finish materials based on lateral flame spread over a vertical sample. True False F8.1 Describe the triad of fire growth. F8.2 Liquid pool fires reach steady burning conditions within seconds after ignition. True False F8.3 The heat of gasification of liquid fuels is typically less than 1 kJ/g. between 1 and 3 kJ/g. greater than 3 kJ/g. F8.4 The heat flux from the flame to the surface of real burning objects can usually be determined with sufficient accuracy so that reasonable burning rate predictions can be made. True False F8.5 The mass burning flux generally associated with extinction is 0.5 g/m2s. 5 g/m2s. 50 g/m2s. F8.6 The mass burning flux of a liquid pool fire is a function of only the pool diameter. only the fuel type. pool diameter and fuel type. F8.7 The energy release rate of real objects can be measured in an oxygen bomb calorimeter. an oxygen consumption calorimeter. a room/corner test. F8.8 The peak energy release rate of typical domestic upholstered furniture can be as high as 3000 kW. True False F8.9 Draw a typical curve of the mass burning flux of a char forming fuel as a function of time. F8.10 A fast fire as defined in NFPA 72B grows proportionally to t2 and reaches an energy release rate of 1 MW in 75 sec. 150 sec. 300 sec. F9.1 Air entrainment into turbulent pool fire flames is due to buoyancy. True False F9.2 The frequency of vortex shedding in turbulent pool fire flames increases with pool diameter. decreases with pool diameter. is independent of pool diameter. F9.3 The height of turbulent jet flames for a given fuel type and orifice size is independent of energy release rate. True False F9.4 The exit velocities of fuel vapors leaving a solid or liquid pool fire surface are responsible for entrainment of air in the plume. True False F9.5 The height of a turbulent pool fire flame is a function of only energy release rate. only pool diameter. energy release rate and pool diameter. F9.6 Turbulent pool fire flame heights fluctuate in time within a factor of 2. True False F9.7 The Q* value for jet fires is 102 or greater. 104 or greater. 106 or greater. F9.8 The temperature in the continuous flame region of moderate size turbulent pool fires is approximately 820°C. True False F9.9 The temperature at the maximum flame height of a turbulent pool fire flame is approximately 1200°C. 800°C. 300°C. F9.10 The adiabatic flame temperature of hydrocarbon fuels is 1700-2000°C. 2000-2300°C. 2300-2600°C. F10.1 The stoichiometric air to fuel mass ratio of hydrocarbon fuels is of the order of 1.5 g/g. 15 g/g. 150 g/g. F10.2 Give two examples of products of incomplete combustion that occur in fires. F10.3 Slight amounts of products of incomplete combustion are generated in overventilated fires. True False F10.4 The CO yield of a fire is a function of only the fuel involved. only the ventilation conditions. the fuel and the ventilation conditions. F10.5 A carboxyhemoglobin level of 40% in the blood is usually lethal. True (doubt) False F10.6 Carbon monoxide is the leading killer of people in fires. True False F10.7 HCN is a narcotic gas. an irritant gas. a fuel vapor. F10.8 The hazard to humans from narcotic gases is a function of only the concentration of the gas. only the duration of exposure. the product of concentration and duration of exposure. F10.9 The effects on lethality of CO, HCN, and reduced O2 are additive. True False F10.10 Irritant gases typically cause post-exposure fatalities. True False F10.11 Visibility through smoke improves with increasing optical density. True False F10.12 Heat stress occurs when the skin is exposed to a heat flux of 1 kW/m2. the skin reaches a temperature of 45°C. the body’s core temperature reaches 41°C.

F7.10 The flame spread rate through porous solids increases with … Read More...
1 | P a g e Lecture #2: Abortion (Warren) While studying this topic, we will ask whether it is morally permissible to intentionally terminate a pregnancy and, if so, whether certain restrictions should be placed upon such practices. Even though we will most often be speaking of terminating a fetus, biologists make further classifications: the zygote is the single cell resulting from the fusion of the egg and the sperm; the morula is the cluster of cells that travels through the fallopian tubes; the blastocyte exists once an outer shell of cells has formed around an inner group of cells; the embryo exists once the cells begin to take on specific functions (around the 15th day); the fetus comes into existence in the 8th week when the embryo gains a basic structural resemblance to the adult. Given these distinctions, there are certain kinds of non-fetal abortion—such as usage of RU-486 (the morning-after “abortion pill”)—though most of the writers we will study refer to fetal abortions. So now let us consider the “Classical Argument against Abortion”, which has been very influential: P1) It is wrong to kill innocent persons. P2) A fetus is an innocent person. C) It is wrong to kill a fetus. (Note that this argument has received various formulations, including those from Warren and Thomson which differ from the above. For this course, we will refer to the above formulation as the “Classical Argument”.) Before evaluating this argument, we should talk about terminology: A person is a member of the moral community; i.e., someone who has rights and/or duties. ‘Persons’ is the plural of ‘person’. ‘Person’ can be contrasted with ‘human being’; a human being is anyone who is genetically human (i.e., a member of Homo sapiens). ‘People’ (or ‘human beings’) is the plural of ‘human being’. Why does this matter? First, not all persons are human beings. For example, consider an alien from another planet who mentally resembled us. If he were to visit Earth, it would be morally reprehensible to kick him or to set him on fire because of the pain and suffering that these acts would cause. And, similarly, the alien would be morally condemnable if he were to propagate such acts on us; he has a moral duty not to act in those ways (again, assuming a certain mental resemblance to us). So, even though this alien is not a human being, he is nevertheless a person with the associative rights and/or duties. 2 | P a g e And, more controversially, maybe not all human beings are persons. For example, anencephalic infants—i.e., ones born without cerebral cortexes and therefore with severely limited cognitive abilities—certainly do not have duties since they are not capable of rational thought and autonomous action. Some philosophers have even argued that they do not have rights. Now let us return to the Classical Argument. It is valid insofar as, if the premises are true, then the conclusion has to be true. But maybe it commits equivocation, which is to say that it uses the same word in multiple senses; equivocation is an informal fallacy (i.e., attaches to arguments that are formally valid but otherwise fallacious). Consider the following: P1) I put my money in the bank. P2) The bank borders the river. C) I put my money somewhere that borders the river. This argument equivocates since ‘bank’ is being used in two different senses: in P1 it is used to represent a financial institution and, in P2, it is used to represent a geological feature. Returning to the classical argument, it could be argued that ‘person’ is being used in two different senses: in P1 it is used in its appropriate moral sense and, in P2, it is inappropriately used instead of ‘human being’. The critic might suggest that a more accurate way to represent the argument would be as follows: P1) It is wrong to kill innocent persons. P2) A fetus is a human being. C) It is wrong to kill a fetus. This argument is obviously invalid. So one way to criticize the Classical Argument is to say that it conflates two different concepts—viz., ‘person’ and ‘human being’—and therefore commits equivocation. However, the more straightforward way to attack the Classical Argument is just to deny its second premise and thus contend that the argument is unsound. This is the approach that Mary Anne Warren takes in “On the Moral and Legal Status of Abortion”. Why does Warren think that the second premise is false? Remember that we defined a person as “a member of the moral community.” And we said that an alien, for example, could be afforded moral status even though it is not a human being. Why do we think that this alien should not be tortured or set on fire? Warren thinks that, intuitively, we think that membership in the moral community is based upon possession of the following traits: 3 | P a g e 1. Consciousness of objects and events external and/or internal to the being and especially the capacity to feel pain; 2. Reasoning or rationality (i.e., the developed capacity to solve new and relatively complex problems); 3. Self-motivated activity (i.e., activity which is relatively independent of either genetic or direct external control); 4. Capacity to communicate (not necessarily verbal or linguistic); and 5. Possession of self-concepts and self-awareness. Warren then admits that, though all of the items on this list look promising, we need not require that a person have all of the items on this list. (4) is perhaps the most expendable: imagine someone who is fully paralyzed as well as deaf, these incapacities, which preclude communication, are not sufficient to justify torture. Similarly, we might be able to imagine certain psychological afflictions that negate (5) without compromising personhood. Warren suspects that (1) and (2) are might be sufficient to confer personhood, and thinks that (1)-(3) “quite probably” are sufficient. Note that, if she is right, we would not be able to torture chimps, let us say, but we could set plants on fire (and most likely ants as well). However, given Warren’s aims, she does not need to specify which of these traits are necessary or sufficient for personhood; all that she wants to observe is that the fetus has none of them! Therefore, regardless of which traits we want to require, Warren thinks that the fetus is not a person. Therefore she thinks that the Classical Argument is unsound and should be rejected. Even if we accept Warren’s refutation of the second premise, we might be inclined to say that, while the fetus is not (now) a person, it is a potential person: the fetus will hopefully mature into a being that possesses all five of the traits on Warren’s list. We might then propose the following adjustment to the Classical Argument: P1) It is wrong to kill all innocent persons. P2) A fetus is a potential person. C) It is wrong to kill a fetus. However, this argument is invalid. Warren grants that potentiality might serve as a prima facie reason (i.e., a reason that has some moral weight but which might be outweighed by other considerations) not to abort a fetus, but potentiality alone is insufficient to grant the fetus a moral right against being terminated. By analogy, consider the following argument: 4 | P a g e P1) The President has the right to declare war. P2) Mary is a potential President. C) Mary has the right to declare war. This argument is invalid since the premises are both true and the conclusion is false. By parity, the following argument is also invalid: P1) A person has a right to life. P2) A fetus is a potential person. C) A fetus has a right to life. Thus Warren thinks that considerations of potentiality are insufficient to undermine her argument that fetuses—which are potential persons but, she thinks, not persons—do not have a right to life.

1 | P a g e Lecture #2: Abortion (Warren) While studying this topic, we will ask whether it is morally permissible to intentionally terminate a pregnancy and, if so, whether certain restrictions should be placed upon such practices. Even though we will most often be speaking of terminating a fetus, biologists make further classifications: the zygote is the single cell resulting from the fusion of the egg and the sperm; the morula is the cluster of cells that travels through the fallopian tubes; the blastocyte exists once an outer shell of cells has formed around an inner group of cells; the embryo exists once the cells begin to take on specific functions (around the 15th day); the fetus comes into existence in the 8th week when the embryo gains a basic structural resemblance to the adult. Given these distinctions, there are certain kinds of non-fetal abortion—such as usage of RU-486 (the morning-after “abortion pill”)—though most of the writers we will study refer to fetal abortions. So now let us consider the “Classical Argument against Abortion”, which has been very influential: P1) It is wrong to kill innocent persons. P2) A fetus is an innocent person. C) It is wrong to kill a fetus. (Note that this argument has received various formulations, including those from Warren and Thomson which differ from the above. For this course, we will refer to the above formulation as the “Classical Argument”.) Before evaluating this argument, we should talk about terminology: A person is a member of the moral community; i.e., someone who has rights and/or duties. ‘Persons’ is the plural of ‘person’. ‘Person’ can be contrasted with ‘human being’; a human being is anyone who is genetically human (i.e., a member of Homo sapiens). ‘People’ (or ‘human beings’) is the plural of ‘human being’. Why does this matter? First, not all persons are human beings. For example, consider an alien from another planet who mentally resembled us. If he were to visit Earth, it would be morally reprehensible to kick him or to set him on fire because of the pain and suffering that these acts would cause. And, similarly, the alien would be morally condemnable if he were to propagate such acts on us; he has a moral duty not to act in those ways (again, assuming a certain mental resemblance to us). So, even though this alien is not a human being, he is nevertheless a person with the associative rights and/or duties. 2 | P a g e And, more controversially, maybe not all human beings are persons. For example, anencephalic infants—i.e., ones born without cerebral cortexes and therefore with severely limited cognitive abilities—certainly do not have duties since they are not capable of rational thought and autonomous action. Some philosophers have even argued that they do not have rights. Now let us return to the Classical Argument. It is valid insofar as, if the premises are true, then the conclusion has to be true. But maybe it commits equivocation, which is to say that it uses the same word in multiple senses; equivocation is an informal fallacy (i.e., attaches to arguments that are formally valid but otherwise fallacious). Consider the following: P1) I put my money in the bank. P2) The bank borders the river. C) I put my money somewhere that borders the river. This argument equivocates since ‘bank’ is being used in two different senses: in P1 it is used to represent a financial institution and, in P2, it is used to represent a geological feature. Returning to the classical argument, it could be argued that ‘person’ is being used in two different senses: in P1 it is used in its appropriate moral sense and, in P2, it is inappropriately used instead of ‘human being’. The critic might suggest that a more accurate way to represent the argument would be as follows: P1) It is wrong to kill innocent persons. P2) A fetus is a human being. C) It is wrong to kill a fetus. This argument is obviously invalid. So one way to criticize the Classical Argument is to say that it conflates two different concepts—viz., ‘person’ and ‘human being’—and therefore commits equivocation. However, the more straightforward way to attack the Classical Argument is just to deny its second premise and thus contend that the argument is unsound. This is the approach that Mary Anne Warren takes in “On the Moral and Legal Status of Abortion”. Why does Warren think that the second premise is false? Remember that we defined a person as “a member of the moral community.” And we said that an alien, for example, could be afforded moral status even though it is not a human being. Why do we think that this alien should not be tortured or set on fire? Warren thinks that, intuitively, we think that membership in the moral community is based upon possession of the following traits: 3 | P a g e 1. Consciousness of objects and events external and/or internal to the being and especially the capacity to feel pain; 2. Reasoning or rationality (i.e., the developed capacity to solve new and relatively complex problems); 3. Self-motivated activity (i.e., activity which is relatively independent of either genetic or direct external control); 4. Capacity to communicate (not necessarily verbal or linguistic); and 5. Possession of self-concepts and self-awareness. Warren then admits that, though all of the items on this list look promising, we need not require that a person have all of the items on this list. (4) is perhaps the most expendable: imagine someone who is fully paralyzed as well as deaf, these incapacities, which preclude communication, are not sufficient to justify torture. Similarly, we might be able to imagine certain psychological afflictions that negate (5) without compromising personhood. Warren suspects that (1) and (2) are might be sufficient to confer personhood, and thinks that (1)-(3) “quite probably” are sufficient. Note that, if she is right, we would not be able to torture chimps, let us say, but we could set plants on fire (and most likely ants as well). However, given Warren’s aims, she does not need to specify which of these traits are necessary or sufficient for personhood; all that she wants to observe is that the fetus has none of them! Therefore, regardless of which traits we want to require, Warren thinks that the fetus is not a person. Therefore she thinks that the Classical Argument is unsound and should be rejected. Even if we accept Warren’s refutation of the second premise, we might be inclined to say that, while the fetus is not (now) a person, it is a potential person: the fetus will hopefully mature into a being that possesses all five of the traits on Warren’s list. We might then propose the following adjustment to the Classical Argument: P1) It is wrong to kill all innocent persons. P2) A fetus is a potential person. C) It is wrong to kill a fetus. However, this argument is invalid. Warren grants that potentiality might serve as a prima facie reason (i.e., a reason that has some moral weight but which might be outweighed by other considerations) not to abort a fetus, but potentiality alone is insufficient to grant the fetus a moral right against being terminated. By analogy, consider the following argument: 4 | P a g e P1) The President has the right to declare war. P2) Mary is a potential President. C) Mary has the right to declare war. This argument is invalid since the premises are both true and the conclusion is false. By parity, the following argument is also invalid: P1) A person has a right to life. P2) A fetus is a potential person. C) A fetus has a right to life. Thus Warren thinks that considerations of potentiality are insufficient to undermine her argument that fetuses—which are potential persons but, she thinks, not persons—do not have a right to life.

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

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

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Chapter 07 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 7 Reading Quiz Question 17 Part A A lake is currently at high pool, with the same amount of water flowing into the lake as is flowing over the spillway. Which of the following temporary changes would increase the resident time of water in this lake? ANSWER: Chapter 7 Reading Quiz Question 16 Part A A large reservoir behind a dam is rapidly rising, as rain and melting snow add more water than is being released out of the dam’s spillway. In this situation, _____. ANSWER: Chapter 7 Reading Quiz Question 1 Part A Which one of the following statements is correct? ANSWER: Double the rate of water flow into the lake and double the rate of water flow out of the lake, while keeping the lake at the same level. Keep the inflow into the lake the same, but release twice as much water from the lake, resulting in a lowering of the lake level. Decrease the inflow into the lake by half, and decrease the outflow of the lake by half. None of the choices would increase the resident time in the lake. the net flux is positive and the capital of water within the reservoir is decreasing the net flux is positive and the capital of water within the reservoir is increasing the net flux is negative and the capital of water within the reservoir is increasing the net flux is negative and the capital of water within the reservoir is decreasing Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 1 of 8 5/21/2014 8:01 PM Chapter 7 Reading Quiz Question 18 Part A A raging river cascades down a granite mountain and eventually reaches the ocean. At the mouth of the river is a beautiful sandy beach composed of fine grains of granite particles from the river. The entire process of producing this sand is a result of _____. ANSWER: Chapter 7 Reading Quiz Question 4 Part A The physical and chemical properties of soils are primarily determined by _____. ANSWER: Chapter 7 Reading Quiz Question 19 Part A Several inches of rain fall over a field of tall corn, soaking into the soil and draining into ditches. Within an hour, there is no standing water and the humidity over the field rises quickly. At a nearby shopping mall, the rainwater fell onto blacktop and drained to sewer pipes, which carried the water directly into a stream. Which of the following occurred in The cycling time of an element or molecule in an ecosystem is equal to the sum of all the flux times. The cycling time is how long it takes an element or molecule to pass through a biogeochemical cycle. The cycling time of water moving through an ecosystem is typically shorter than the resident time in any pool in this system. The amount of time that water spends in an ocean is the cycling time. mineral evaporation erosion, weathering, transport, and then deposition erosion, dissolution, and precipitation organisms consuming and eroding granite the properties of rock from which the soils develop the amount of precipitation that the soil experiences the range of temperatures that the soil experiences the types of animals that live and move through the soils Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 2 of 8 5/21/2014 8:01 PM the cornfield but not in the parking lot? ANSWER: Chapter 7 Reading Quiz Question 6 Part A Most of the water on Earth is found in _____. ANSWER: Chapter 7 Reading Quiz Question 5 Part A Which one of the following primarily results from the effects of solar energy? ANSWER: Chapter 7 Reading Quiz Question 20 Part A A rural Minnesota farmer grows a variety of vegetables to feed her family. In addition, she cuts down some of her dead trees for firewood to heat her home in the winter. This farmer is adding to the flux of the carbon cycle in her region by _____. precipitation evaporation runoff transpiration the polar ice caps lakes and streams aquifers the oceans evaporation of water from a lake the formation of ice on the top of a pond movement of ocean tides the movement of water over a waterfall Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 3 of 8 5/21/2014 8:01 PM ANSWER: Chapter 7 Reading Quiz Question 8 Part A In a terrestrial ecosystem, most carbon is stored in the biomass of _____. ANSWER: Chapter 7 Reading Quiz Question 7 Part A In which of the following countries would we expect that the terrestrial ecosystems have the highest net primary production and biomass? ANSWER: Chapter 7 Reading Quiz Question 22 Part A Some farmers in the Midwest of the United States rotate their crops from year to year, switching from soybeans to corn on the same fields. What is one of the advantages of doing this? encouraging photosynthesis as she raises crops burning carbon-based fuels by consuming vegetables grown on her farm All of the choices are correct. the animals living there air the top layers of soil containing dead organisms living plants China Australia Brazil United States Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 4 of 8 5/21/2014 8:01 PM ANSWER: Chapter 7 Reading Quiz Question 10 Part A Most nitrogen enters the biosphere through the process of _____ ANSWER: Chapter 7 Reading Quiz Question 9 Part A Where do we expect to find the least amount of nitrogen? ANSWER: Chapter 7 Reading Quiz Question 12 Part A Along the west coast of the United States, upwellings bring deep ocean waters to the surface, carrying with them _____, which greatly increases NPP. ANSWER: The corn crop benefits from reactive nitrogen added to the soil by the soybean crop. Both crops require the same fertilizing supplies, so farmers save by buying fertilizer in bulk. Soybeans add large amounts of carbon dioxide to the soil, which helps the corn crop. Corn adds large amounts of phosphorus to the soil, which helps the soybean crop. nitrogen fixation in which bacteria convert N2 to NH3 cellular respiration, in which animals convert N2 to NH4 fermentation in which bacteria convert N2 to HNO3 photosynthesis, in which plants convert N2 to NO2 in Earth’s crust in plants in animals in the atmosphere Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 5 of 8 5/21/2014 8:01 PM Chapter 7 Reading Quiz Question 11 Part A Which one of the following statements about the carbon, phosphorus, and nitrogen cycles is true? ANSWER: Chapter 7 Reading Quiz Question 24 Part A A large coal-burning power plant is about 50 miles upwind from a lake that used to be popular for fishing. But now, just five years after the plant was constructed, the fish populations are decreasing dramatically. Which one of the following impacts of this coal-burning power plant is most likely hurting the fish populations in this downwind lake? ANSWER: Chapter 7 Reading Quiz Question 14 Part A Which one of the following statements about sulfur is correct? ANSWER: oxygen phosphate carbon sulfur Phosphorus is virtually absent in the atmosphere. The major source of carbon used by plants is the soil. Bacteria drive the phosphorus cycle. The major source of nitrogen used by plants is the air. insufficient sunlight reaching the lake low oxygen levels from burning fossil fuels eutrophication of the lake acidification of the lake Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 6 of 8 5/21/2014 8:01 PM Chapter 7 Reading Quiz Question 13 Part A Nitrogen and sulfur are important to all organisms because they are important constituents of _____. ANSWER: Chapter 7 Reading Quiz Question 25 Part A In Iowa, a small, deep lake in the summer becomes stratified with warmer, less-dense water at the surface and colder, denser water near the bottom. As fall air temperatures decrease, the surface water cools and then drops toward the bottom, mixing the lake levels together. As a result of this mixing, _____. ANSWER: Chapter 7 Reading Quiz Question 15 Part A A fire spreads across hundreds of acres of prairie, burning most of the plant parts above the ground. Compared to before the fire, right after this fire the pool of nutrients in the prairie plants _____. The main pool of sulfur is in the atmosphere where the flux is high and the residence time is long. The main pool of sulfur is in rocks. The flux of sulfur through the atmosphere is high and the residence is short. The main pool of sulfur is in the atmosphere where the flux is low and the residence time is long. The main pool of sulfur is in rocks. The flux of sulfur through the atmosphere is low and the residence is short. nucleic acids glucose phosphates some amino acids nitrogen and phosphorus are added to the lake nitrogen and phosphorus decrease near the surface of the lake nitrogen and phosphorus increase near the surface of the lake None of the choices is correct. Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 7 of 8 5/21/2014 8:01 PM ANSWER: Score Summary: Your score on this assignment is 0.0%. You received 0 out of a possible total of 21 points. and the soil decreases increases and the pool of nutrients in the soil decreases and the soil increases decreases and the pool of nutrients in the soil increases Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 8 of 8 5/21/2014 8:01 PM

Chapter 07 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 7 Reading Quiz Question 17 Part A A lake is currently at high pool, with the same amount of water flowing into the lake as is flowing over the spillway. Which of the following temporary changes would increase the resident time of water in this lake? ANSWER: Chapter 7 Reading Quiz Question 16 Part A A large reservoir behind a dam is rapidly rising, as rain and melting snow add more water than is being released out of the dam’s spillway. In this situation, _____. ANSWER: Chapter 7 Reading Quiz Question 1 Part A Which one of the following statements is correct? ANSWER: Double the rate of water flow into the lake and double the rate of water flow out of the lake, while keeping the lake at the same level. Keep the inflow into the lake the same, but release twice as much water from the lake, resulting in a lowering of the lake level. Decrease the inflow into the lake by half, and decrease the outflow of the lake by half. None of the choices would increase the resident time in the lake. the net flux is positive and the capital of water within the reservoir is decreasing the net flux is positive and the capital of water within the reservoir is increasing the net flux is negative and the capital of water within the reservoir is increasing the net flux is negative and the capital of water within the reservoir is decreasing Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 1 of 8 5/21/2014 8:01 PM Chapter 7 Reading Quiz Question 18 Part A A raging river cascades down a granite mountain and eventually reaches the ocean. At the mouth of the river is a beautiful sandy beach composed of fine grains of granite particles from the river. The entire process of producing this sand is a result of _____. ANSWER: Chapter 7 Reading Quiz Question 4 Part A The physical and chemical properties of soils are primarily determined by _____. ANSWER: Chapter 7 Reading Quiz Question 19 Part A Several inches of rain fall over a field of tall corn, soaking into the soil and draining into ditches. Within an hour, there is no standing water and the humidity over the field rises quickly. At a nearby shopping mall, the rainwater fell onto blacktop and drained to sewer pipes, which carried the water directly into a stream. Which of the following occurred in The cycling time of an element or molecule in an ecosystem is equal to the sum of all the flux times. The cycling time is how long it takes an element or molecule to pass through a biogeochemical cycle. The cycling time of water moving through an ecosystem is typically shorter than the resident time in any pool in this system. The amount of time that water spends in an ocean is the cycling time. mineral evaporation erosion, weathering, transport, and then deposition erosion, dissolution, and precipitation organisms consuming and eroding granite the properties of rock from which the soils develop the amount of precipitation that the soil experiences the range of temperatures that the soil experiences the types of animals that live and move through the soils Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 2 of 8 5/21/2014 8:01 PM the cornfield but not in the parking lot? ANSWER: Chapter 7 Reading Quiz Question 6 Part A Most of the water on Earth is found in _____. ANSWER: Chapter 7 Reading Quiz Question 5 Part A Which one of the following primarily results from the effects of solar energy? ANSWER: Chapter 7 Reading Quiz Question 20 Part A A rural Minnesota farmer grows a variety of vegetables to feed her family. In addition, she cuts down some of her dead trees for firewood to heat her home in the winter. This farmer is adding to the flux of the carbon cycle in her region by _____. precipitation evaporation runoff transpiration the polar ice caps lakes and streams aquifers the oceans evaporation of water from a lake the formation of ice on the top of a pond movement of ocean tides the movement of water over a waterfall Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 3 of 8 5/21/2014 8:01 PM ANSWER: Chapter 7 Reading Quiz Question 8 Part A In a terrestrial ecosystem, most carbon is stored in the biomass of _____. ANSWER: Chapter 7 Reading Quiz Question 7 Part A In which of the following countries would we expect that the terrestrial ecosystems have the highest net primary production and biomass? ANSWER: Chapter 7 Reading Quiz Question 22 Part A Some farmers in the Midwest of the United States rotate their crops from year to year, switching from soybeans to corn on the same fields. What is one of the advantages of doing this? encouraging photosynthesis as she raises crops burning carbon-based fuels by consuming vegetables grown on her farm All of the choices are correct. the animals living there air the top layers of soil containing dead organisms living plants China Australia Brazil United States Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 4 of 8 5/21/2014 8:01 PM ANSWER: Chapter 7 Reading Quiz Question 10 Part A Most nitrogen enters the biosphere through the process of _____ ANSWER: Chapter 7 Reading Quiz Question 9 Part A Where do we expect to find the least amount of nitrogen? ANSWER: Chapter 7 Reading Quiz Question 12 Part A Along the west coast of the United States, upwellings bring deep ocean waters to the surface, carrying with them _____, which greatly increases NPP. ANSWER: The corn crop benefits from reactive nitrogen added to the soil by the soybean crop. Both crops require the same fertilizing supplies, so farmers save by buying fertilizer in bulk. Soybeans add large amounts of carbon dioxide to the soil, which helps the corn crop. Corn adds large amounts of phosphorus to the soil, which helps the soybean crop. nitrogen fixation in which bacteria convert N2 to NH3 cellular respiration, in which animals convert N2 to NH4 fermentation in which bacteria convert N2 to HNO3 photosynthesis, in which plants convert N2 to NO2 in Earth’s crust in plants in animals in the atmosphere Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 5 of 8 5/21/2014 8:01 PM Chapter 7 Reading Quiz Question 11 Part A Which one of the following statements about the carbon, phosphorus, and nitrogen cycles is true? ANSWER: Chapter 7 Reading Quiz Question 24 Part A A large coal-burning power plant is about 50 miles upwind from a lake that used to be popular for fishing. But now, just five years after the plant was constructed, the fish populations are decreasing dramatically. Which one of the following impacts of this coal-burning power plant is most likely hurting the fish populations in this downwind lake? ANSWER: Chapter 7 Reading Quiz Question 14 Part A Which one of the following statements about sulfur is correct? ANSWER: oxygen phosphate carbon sulfur Phosphorus is virtually absent in the atmosphere. The major source of carbon used by plants is the soil. Bacteria drive the phosphorus cycle. The major source of nitrogen used by plants is the air. insufficient sunlight reaching the lake low oxygen levels from burning fossil fuels eutrophication of the lake acidification of the lake Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 6 of 8 5/21/2014 8:01 PM Chapter 7 Reading Quiz Question 13 Part A Nitrogen and sulfur are important to all organisms because they are important constituents of _____. ANSWER: Chapter 7 Reading Quiz Question 25 Part A In Iowa, a small, deep lake in the summer becomes stratified with warmer, less-dense water at the surface and colder, denser water near the bottom. As fall air temperatures decrease, the surface water cools and then drops toward the bottom, mixing the lake levels together. As a result of this mixing, _____. ANSWER: Chapter 7 Reading Quiz Question 15 Part A A fire spreads across hundreds of acres of prairie, burning most of the plant parts above the ground. Compared to before the fire, right after this fire the pool of nutrients in the prairie plants _____. The main pool of sulfur is in the atmosphere where the flux is high and the residence time is long. The main pool of sulfur is in rocks. The flux of sulfur through the atmosphere is high and the residence is short. The main pool of sulfur is in the atmosphere where the flux is low and the residence time is long. The main pool of sulfur is in rocks. The flux of sulfur through the atmosphere is low and the residence is short. nucleic acids glucose phosphates some amino acids nitrogen and phosphorus are added to the lake nitrogen and phosphorus decrease near the surface of the lake nitrogen and phosphorus increase near the surface of the lake None of the choices is correct. Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 7 of 8 5/21/2014 8:01 PM ANSWER: Score Summary: Your score on this assignment is 0.0%. You received 0 out of a possible total of 21 points. and the soil decreases increases and the pool of nutrients in the soil decreases and the soil increases decreases and the pool of nutrients in the soil increases Chapter 07 Reading Questions http://session.masteringenvironmentalscience.com/myct/assignmentPrintV… 8 of 8 5/21/2014 8:01 PM

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