Non-violence as a rule of love   The mainly essential … Read More...
Faculty of Science Technology and Engineering Department of Physics Senior Laboratory Current balance Objectives When a steady electric current flows perpendicularly across a uniform magnetic field it experiences a force. This experiment aims to investigate this effect, and to determine the direction of the force relative to the current and magnetic field. You will design and perform a series of experiments to show how the magnitude of the force depends upon the current and the length of the conductor that is in the field. Task You are provided with a current balance apparatus (Figure 1), power supply and a magnet. This current balance consists of five loops of conducting wire supported on a pivoted aluminium frame. Current may be made to flow in one or up to five of the loops at a time in either direction. If the end of the loop is situated in a perpendicular magnetic field, when the current is switched on, the magnetic force on the current will unbalance the apparatus. By moving the sliding weights to rebalance it, the magnitude of this magnetic force may be measured. A scale is etched on one arm of the balance, so that the distance moved by the slider can be measured. The circuitry of the balance cannot cope currents greater than 5 Amps, so please do not exceed this level of current. Figure 1: Schematic diagram of current balance apparatus and circuitry. Start by familiarising yourself with the apparatus. Use the two sliding weights to balance the apparatus, then apply a magnetic field to either end of the loop. Pass a current through just one of the conducting loops and observe the direction of the resulting magnetic force, relative to the direction of the current and the applied field. Change the magnitude and direction of the current, observe qualitatively the effect this has on the magnetic force. Having familiarised yourself with the apparatus, you should design and perform a series of quantitative experiments aiming to: (1) determine how the size of the magnetic force is dependant on the size of the current flowing in the conductor. (2) determine how the size of the force is dependant on the length of the conductor which is in the field. (3) measure the value (in Tesla) of the field of the magnet provided. For each of these, the balance should be set up with the magnet positioned at the end of the arm that has the distance scale, and orientated so that the magnetic force will be directed upwards when a current is passed through the conductor. The sliding weight on this arm should be positioned at the zero-mark. The weight on the opposite arm should be adjusted to balance the apparatus in the absence of a current. When a current is applied, you should re-balance the apparatus by moving the weight on the scaled arm outwards, while keeping the opposite weight fixed in position. The distance moved by the weight is directly proportional to the force applied by the magnetic field to the end of the balance. In your report, make sure you discuss why this is the case. Use the position of the sliding weight to quantify the magnetic force as a function of the current applied to the conductor, and of the number of conducting loops through which the current flows. For tasks (1) and (2) you can use the position of the sliding weight as a measure of the force. Look up the relationship that relates the force to the applied field, current and length of conductor in the field. Is this consistent with your data? To complete task (3) you need to determine the magnitude (in Newtons) of the magnetic force from the measurement of the position of the sliding weight. To do this, what other information do you need to know? When you have determined a value for the field, you can measure the field directly using the laboratory’s Gaussmeter for comparison.

Faculty of Science Technology and Engineering Department of Physics Senior Laboratory Current balance Objectives When a steady electric current flows perpendicularly across a uniform magnetic field it experiences a force. This experiment aims to investigate this effect, and to determine the direction of the force relative to the current and magnetic field. You will design and perform a series of experiments to show how the magnitude of the force depends upon the current and the length of the conductor that is in the field. Task You are provided with a current balance apparatus (Figure 1), power supply and a magnet. This current balance consists of five loops of conducting wire supported on a pivoted aluminium frame. Current may be made to flow in one or up to five of the loops at a time in either direction. If the end of the loop is situated in a perpendicular magnetic field, when the current is switched on, the magnetic force on the current will unbalance the apparatus. By moving the sliding weights to rebalance it, the magnitude of this magnetic force may be measured. A scale is etched on one arm of the balance, so that the distance moved by the slider can be measured. The circuitry of the balance cannot cope currents greater than 5 Amps, so please do not exceed this level of current. Figure 1: Schematic diagram of current balance apparatus and circuitry. Start by familiarising yourself with the apparatus. Use the two sliding weights to balance the apparatus, then apply a magnetic field to either end of the loop. Pass a current through just one of the conducting loops and observe the direction of the resulting magnetic force, relative to the direction of the current and the applied field. Change the magnitude and direction of the current, observe qualitatively the effect this has on the magnetic force. Having familiarised yourself with the apparatus, you should design and perform a series of quantitative experiments aiming to: (1) determine how the size of the magnetic force is dependant on the size of the current flowing in the conductor. (2) determine how the size of the force is dependant on the length of the conductor which is in the field. (3) measure the value (in Tesla) of the field of the magnet provided. For each of these, the balance should be set up with the magnet positioned at the end of the arm that has the distance scale, and orientated so that the magnetic force will be directed upwards when a current is passed through the conductor. The sliding weight on this arm should be positioned at the zero-mark. The weight on the opposite arm should be adjusted to balance the apparatus in the absence of a current. When a current is applied, you should re-balance the apparatus by moving the weight on the scaled arm outwards, while keeping the opposite weight fixed in position. The distance moved by the weight is directly proportional to the force applied by the magnetic field to the end of the balance. In your report, make sure you discuss why this is the case. Use the position of the sliding weight to quantify the magnetic force as a function of the current applied to the conductor, and of the number of conducting loops through which the current flows. For tasks (1) and (2) you can use the position of the sliding weight as a measure of the force. Look up the relationship that relates the force to the applied field, current and length of conductor in the field. Is this consistent with your data? To complete task (3) you need to determine the magnitude (in Newtons) of the magnetic force from the measurement of the position of the sliding weight. To do this, what other information do you need to know? When you have determined a value for the field, you can measure the field directly using the laboratory’s Gaussmeter for comparison.

Abstract   The present experiment aims to investigate the effect … 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

info@checkyourstudy.com

Intellectual (thinking) skills   Strongly Agree Agree Disagree Strongly … Read More...