CP Snr and Hon Freshmen Study Guide

Transcription

1 CP Snr and Hon Freshmen Study Guide Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Displacement is which of the following types of quantities? a. vector b. scalar c. magnitude d. dimensional 2. Changing the positive direction in a reference frame to the opposite direction does not change the sign of which of the following quantities? a. velocity b. average velocity c. speed d. displacement 3. An x vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the velocity of the ball is zero. We can be positive that at t = 5 s, a. the slope of the curve is non-zero. b. the ball has stopped. c. the acceleration is constant. d. the curve is at x = 0, t = A v vs. t graph is drawn for a ball moving in one direction. The graph starts at the origin and at t = 5 s the acceleration of the ball is zero. We know that at t = 5 s, a. the slope of the curve is non-zero. b. the velocity of the ball is not changing. c. the curve is not crossing the time axis. d. the curve is at v = 0, t = The value of an object's acceleration may be characterized in equivalent words by which of the following? a. displacement b. rate of change of displacement c. velocity d. rate of change of velocity 6. A baseball catcher throws a ball vertically upward and catches it in the same spot when it returns to his mitt. At what point in the ball's path does it experience zero velocity and non-zero acceleration at the same time? a. midway on the way up b. at the top of its trajectory c. the instant it leaves the catcher's hand d. the instant before it arrives in the catcher's mitt 7. Which type of quantity is characterized by both magnitude and direction? a. scalar b. vector c. trigonometric d. algebraic variable

2 8. Which of the following is an example of a vector quantity? a. velocity b. temperature c. volume d. mass 9. Which of the following is an example of the type of force that acts at a distance? a. gravitational b. magnetic c. electrical d. all of the above 10. The statement by Newton that "for every action there is an opposite but equal reaction" is regarded as which of his laws of motion? a. first b. second c. third d. fourth 11. A horizontal force of 100 N is applied to move a 45-kg cart across a 9.0-m level surface. What work is done by the 100-N force? a. 405 J b. 500 J c. 900 J d J 12. As an object is lowered into a deep hole in the surface of the earth, which of the following must be assumed in regard to its potential energy? a. increase b. decrease c. remain constant d. cannot tell from the information given 13. A 2.00-kg ball has zero kinetic and potential energy. Ernie drops the ball into a 10.0-m-deep well. Just before the ball hits the bottom, the sum of its kinetic and potential energy is: a. zero. b. 196 J. c. 196 J. d. 392 J. 14. A ball with original momentum +6.0 kg m/s hits a wall and bounces straight back without losing any kinetic energy. The change in momentum of the ball is: a. 0. b. 6.0 kg m/s. c kg m/s. d kg m/s. 15. The units of impulse are equivalent to: a. those of energy. b. N m. c. kg m/s. d. those of force.

3 16. The law of conservation of momentum is applicable to systems made up of objects described by which of the following? a. macroscopic b. microscopic c. interacting through friction d. All the above choices are valid. 17. If the momentum of an object is tripled, its kinetic energy will change by what factor? a. zero b. one-third c. three d. nine 18. A billiard ball collides in an elastic head-on collision with a second identical ball. What is the kinetic energy of the system after the collision compared to that before collision? a. the same as b. one fourth c. twice d. four times 19. In a two-body collision, if the momentum of the system is conserved, then which of the following best describes the kinetic energy after the collision? a. must be less b. must also be conserved c. may also be conserved d. is doubled in value 20. In a two-body collision, if the kinetic energy of the system is conserved, then which of the following best describes the momentum after the collision? a. must be less b. must also be conserved c. may also be conserved d. is doubled in value 21. In a system with two moving objects, when a collision occurs between the objects: a. the total kinetic energy is always conserved. b. the total momentum is always conserved. c. the total kinetic energy and total momentum are always conserved. d. neither the kinetic energy nor the momentum is conserved. 22. When an object is moving with uniform circular motion, the object s tangential speed a. is circular. b. is perpendicular to the plane of motion. c. is constant. d. is directed toward the center of motion. 23. The centripetal force on an object in circular motion is a. perpendicular to the plane of the object s motion. b. in the plane of the object s motion and perpendicular to the tangential speed. c. in the plane of the object s motion and in the same direction as the tangential speed. d. in the plane of the object s motion and in the direction opposite the tangential speed.

4 24. When a car makes a sharp left turn, what causes the passengers to move toward the right side of the car? a. centripetal acceleration c. centrifugal force b. centripetal force d. inertia 25. A ladybug rests on the bottom of a tin can that is being whirled horizontally on the end of a string. Since the ladybug, like the can, moves in a circle, there must be a force on it. What exerts this force? a. Gravity b. The string c. There is no force acting on it. d. The can e. Your hand 26. A car travels in a circle with constant speed. The net force on the car a. is zero because the car is not accelerating. b. is directed forward, in the direction of travel. c. is directed toward the center of the curve. d. none of the above 27. If the momentum of an object changes and its mass remains constant, a. it is accelerating (or decelerating). b. there is a force acting on it. c. its velocity is changing. d. all of the above 28. In order to increase the final momentum of a golf ball, we could a. increase the force acting on it. b. follow through when hitting the ball. c. increase the time of contact with the ball. d. swing as hard as possible. e. all of the above 29. 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. 30. A collision is considered elastic if a. there is no lasting deformation. b. the objects don t stick together. c. the objects that collide don't get warmer. d. after the collision, the objects have the same shape as before the collision. e. all of the above 31. Suppose a girl is standing on a pond where there is no friction between her feet and the ice. In order to get off the ice, she can a. bend over touching the ice in front of her and then bring her feet to her hands. b. walk very slowly on tiptoe. c. get on her hands and knees and crawl off the ice. d. throw something in the direction opposite to the way she wants to go. e. all of the above will work

5 32. Which of the following has the largest momentum? a. A large truck parked in a parking lot b. A tightrope walker crossing Niagara Falls c. The science building at your school d. A pickup truck traveling down the highway e. A dog running down the street 33. Suppose a cannon is made of a strong but very light material. Suppose also that the cannonball is more massive than the cannon itself. For such a system a. conservation of momentum would not hold. b. conservation of energy would not hold. c. the target would be a safer place than where the operator is located. d. the force on the cannonball would be greater than the force on the cannon. e. recoil problems would be lessened. 34. In order to catch a ball, a baseball player moves his or her hand backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because a. the time of impact is decreased. b. the time of impact is increased. c. the velocity of the hand is reduced. d. the momentum of impact is reduced. 35. A car traveling along the highway needs a certain amount of force exerted on it to stop. More stopping force may be required when the car has a. less stopping distance. b. more momentum. c. more mass. d. all of the above 36. A cannon fires a cannonball. The speed of the cannonball will be the same as the speed of the recoiling cannon a. if the mass of the cannonball equals the mass of the cannon. b. because momentum is conserved. c. because velocity is conserved. d. because both velocity and momentum are conserved. 37. A moving freight car runs into an identical car at rest on the track. The cars couple together. Compared to the velocity of the first car before the collision, the velocity of the combined cars after the collision is a. zero. b. one half as large. c. the same. d. twice as large. e. More information is needed to say. 38. Two gliders having the same mass and speed move toward each other on an air track and stick together. After the collision, the velocity of the gliders is a. twice the original velocity. b. one half the original velocity. c. zero.

6 d. the same as the original velocity. e. There is not enough information to say. 39. The force that accelerates a rocket into outer space is exerted on the rocket by a. the exhaust gases. b. Earth's gravity. c. atmospheric pressure. d. rocket's wings. 40. Suppose an astronaut in outer space wishes to toss a ball against a very massive and perfectly elastic concrete wall and catch it as it bounces back. If the ball is as massive as the astronaut, then a. the astronaut's time between catches will decrease as the game progresses. b. the astronaut will never catch the first bounce. c. the astronaut will catch one bounce only. d. none of the above 41. A 4.0-kg ball has a momentum of 20.0 kg m/s. What is the ball's speed? a. 0.2 m/s b. 5.0 m/s c m/s d m/s 42. How much farther will a car traveling at 100 km/s skid than the same car traveling at 50 km/s? a. Half as far. b. The same distance. c. Twice as far. d. Four times as far. e. Five times as far. 43. As a pendulum swings back and forth a. at the end points of its swing, its energy is all potential. b. at the lowest part of its swing, its energy is all kinetic. c. kinetic energy is transformed into potential energy. d. potential energy is transformed into kinetic energy. e. all of the above 44. A ball is thrown into the air with 100 J of kinetic energy, which is transformed to gravitational potential energy at the top of its trajectory. When it returns to its original level after encountering air resistance, its kinetic energy is a. 100 J. b. more than 100 J. c. less than 100 J. d. Not enough information given. 45. A heavy object and a light object are released from rest at the same height and time in a vacuum. As they fall, they have equal a. energies. b. weights. c. momenta. d. all of the above

7 46. How many joules of work are done on a box when a force of 25 N pushes it 3 m? a. 1 J b. 3 J c. 8 J d. 25 J e. 75 J 47. How much work is done on a 60-N box of books that you carry horizontally across a 6-m room? a. 0 J b. 6 J c. 10 J d. 60 J e. 360 J 48. If Kelly the skater's speed increases so he has three times the momentum, then his kinetic energy increases by a. one third times. b. three times. c. nine times. d. none of the above (KE remains the same).

8 CP Snr and Hon Freshmen Study Guide Answer Section MULTIPLE CHOICE 1. ANS: A PTS: 1 DIF: 1 TOP: 2.1 Displacement 2. ANS: C PTS: 1 DIF: 1 TOP: 2.2 Velocity 3. ANS: B PTS: 1 DIF: 1 TOP: 2.3 Acceleration 4. ANS: B PTS: 1 DIF: 1 TOP: 2.3 Acceleration 5. ANS: D PTS: 1 DIF: 1 TOP: 2.3 Acceleration 6. ANS: B PTS: 1 DIF: 1 TOP: 2.6 Freely-Falling Objects 7. ANS: B PTS: 1 DIF: 1 TOP: 3.1 Vectors and Their Properties 8. ANS: A PTS: 1 DIF: 1 TOP: 3.1 Vectors and Their Properties 9. ANS: D PTS: 1 DIF: 1 TOP: 4.1 Forces 4.2 Newton's First Law 4.3 Newton's Second Law 4.4 Newton's Third Law 10. ANS: C PTS: 1 DIF: 1 TOP: 4.1 Forces 4.2 Newton's First Law 4.3 Newton's Second Law 4.4 Newton's Third Law 11. ANS: C PTS: 1 DIF: 1 TOP: 5.1 Work 12. ANS: B PTS: 1 DIF: 1 TOP: 5.3 Gravitational Potential Energy 13. ANS: A PTS: 1 DIF: 1 TOP: 5.3 Gravitational Potential Energy 14. ANS: D PTS: 1 DIF: 1 TOP: 6.1 Momentum and Impulse 15. ANS: C PTS: 1 DIF: 1 TOP: 6.1 Momentum and Impulse 16. ANS: D PTS: 1 DIF: 1 TOP: 6.2 Conservation of Momentum 17. ANS: D PTS: 1 DIF: 1 TOP: 6.2 Conservation of Momentum 18. ANS: A PTS: 1 DIF: 1 TOP: 6.3 Collisions 6.4 Glancing Collisions 19. ANS: C PTS: 1 DIF: 1 TOP: 6.3 Collisions 6.4 Glancing Collisions 20. ANS: B PTS: 1 DIF: 1 TOP: 6.3 Collisions 6.4 Glancing Collisions 21. ANS: B PTS: 1 DIF: 1 TOP: 6.3 Collisions 6.4 Glancing Collisions 22. ANS: C PTS: 1 DIF: I OBJ: ANS: B PTS: 1 DIF: I OBJ: ANS: D PTS: 1 DIF: I OBJ: ANS: D PTS: 1 DIF: L2 OBJ: 10.4 Centripetal and Centrifugal Forces KEY: force circular 26. ANS: C PTS: 1 DIF: L2 OBJ: 10.3 Centripetal Force KEY: weight Earth 27. ANS: D PTS: 1 DIF: L2 OBJ: 8.1 Momentum KEY: momentum velocity mass 28. ANS: E PTS: 1 DIF: L2 OBJ: 8.2 Impulse Changes Momentum KEY: momentum force 29. ANS: E PTS: 1 DIF: L2 OBJ: 8.2 Impulse Changes Momentum KEY: impact time 30. ANS: E PTS: 1 DIF: L2 OBJ: 8.5 Collisions

9 KEY: collision elastic 31. ANS: D PTS: 1 DIF: L2 OBJ: 8.4 Conservation of Momentum KEY: opposite force 32. ANS: D PTS: 1 DIF: L2 OBJ: 8.1 Momentum KEY: momentum 33. ANS: C PTS: 1 DIF: L2 OBJ: 8.4 Conservation of Momentum KEY: mass recoil 34. ANS: B PTS: 1 DIF: L2 OBJ: 8.2 Impulse Changes Momentum KEY: impact momentum 35. ANS: D PTS: 1 DIF: L2 OBJ: 8.2 Impulse Changes Momentum KEY: force stop 36. ANS: A PTS: 1 DIF: L2 OBJ: 8.4 Conservation of Momentum KEY: speed cannon mass 37. ANS: B PTS: 1 DIF: L2 OBJ: 8.5 Collisions KEY: velocity collision 38. ANS: C PTS: 1 DIF: L2 OBJ: 8.5 Collisions KEY: collision velocity 39. ANS: A PTS: 1 DIF: L2 OBJ: 8.4 Conservation of Momentum KEY: force acceleration 40. ANS: B PTS: 1 DIF: L2 OBJ: 8.4 Conservation of Momentum KEY: elastic mass 41. ANS: B PTS: 1 DIF: L2 OBJ: 8.1 Momentum KEY: momentum speed 42. ANS: D PTS: 1 DIF: L2 OBJ: 9.5 Kinetic Energy KEY: energy speed 43. ANS: E PTS: 1 DIF: L2 OBJ: 9.6 Work-Energy Theorem KEY: pendulum potential kinetic 44. ANS: C PTS: 1 DIF: L2 OBJ: 9.6 Work-Energy Theorem KEY: kinetic energy potential 45. ANS: E PTS: 1 DIF: L2 OBJ: 9.3 Mechanical Energy KEY: vacuum fall weight 46. ANS: E PTS: 1 DIF: L2 OBJ: 9.1 Work KEY: joule work force 47. ANS: A PTS: 1 DIF: L2 OBJ: 9.1 Work KEY: work distance 48. ANS: C PTS: 1 DIF: L2 OBJ: 9.5 Kinetic Energy KEY: speed momentum kinetic