Dr. Bullock 2.54 centimeter = 1 inch 1 kilometer = 0.62 mile 5280 feet = 1 mile 1 yard = 36 inches TEST 3-A PHSC 1013 Physical Science F = p/t KE = ½ mv2 PE = mgh 3 1 cm water = 1 gram = mass/Volume F = ma aC = v2/r True/False (A=True, B=False) 1. Momentum is a conserved quantity (that remains unchanged) in all types of collisions. -TRUE 2. Energy consumed due to air resistance would be classified as a “reversible process”. -FALSE 3. Kinetic energy is the energy associated with an objects position or configuration. -FALSE 4. Work and energy are both measured in units called “Joules”. -TRUE 5. In elastic collisions the objects tend to rebound from one another. -TRUE 6. Potential energy is a vector quantity. - FALSE 7. Newton was the first to propose the idea that the total motion of the universe was constant. FALSE 8. In inelastic collisions the objects tend to stick together after the collision. -TRUE 9. Energy is sometimes lost during a process. -FALSE 10. In terms of energy, friction is considered an irreversible process. -TRUE 11. Momentum is a vector quantity -TRUE 12. The only way to change an objects momentum is to change it’s velocity -FALSE Multiple Choice (Choose the best possible answer) 13. What is the momentum of a baseball (mass = 1 kg) thrown at a speed of 40 m/s? a) 1 kg m/s b) 40 kg m/s c) 0.4 kg m/s d) 40 m/s e) 1 m/s 14. A stick of dynamite explodes. The pieces (each with a mass of 0.5 kg) of dynamite fly with a speed of 50 m/s. What is the total momentum after the explosion? a) 25 kg m/s b) 0.5 kg m/s c) 50 kg m/s d) 0.01 kg m/s e) 0 kg m/s 15. An object with mass, m travels at a speed v. The same object now travels with speed v/2. What has happened to the object’s kinetic energy? a) Increased by a factor of 2 b) Decreased by a factor of 2 c) Unchanged d) Decreased by a factor of 4 e) Increased by a factor of 6 Dr. Bullock TEST 3-A PHSC 1013 Physical Science For the swinging pendulum pictured at right 16. At what position(s) would it have the greatest kinetic energy? a) A b) B c) C d) D e) E 17. At what position(s) would it have the greatest potential energy? a) A b) B c) A,E d) B,D g E e) C 18. At what position(s) would it have the maximum total energy? a) A,E b) D,B c) C d) D,C,B A D B C e) all positions 19. At what position(s) would it have the greatest speed? a) A, E b) D,B c) C d) D,C,B e) all positions 20. A lump of crud (mass = 10 kg) flies through the air with an initial velocity of 80 m/s and slams into an initially stationary lump of goo (mass 30 kg). If they stick together afterwards, what is the new velocity of the wad of crud and goo? a) 20 m/s b) 40 m/s c) 60 m/s d) 10 m/s e) 4 m/s 21. A freight car weighs 5 times as much as a train engine. If the engine coasts at 12 km/hr and collides into the stationary freight car, how fast are they traveling after they couple together? a) 0 km/hr b) 1 km/hr c) 2 km/hr d) 5 km/hr e) 6 km/hr Consider the following situation pictured at the right. A 100 kg roller coaster cart is 20 meters above the ground on a frictionless track before its initial dive. 22. At which point on the diagram does the cart have it’s maximum potential energy? a) A b) B c) C A B C 23. At which point on the diagram does the cart have it’s maximum kinetic energy? a) A b) B c) C 24. At which point on the diagram does the cart have a combination of both potential and kinetic energy? a) A b) B c) C 25. Its total gravitational potential energy at the top of the track is: a) 100 Joules b) 2000 Joules c) 20000 Joules d) 6000 Joules e) 5 Joules 26. Its total kinetic energy at the bottom of the dive is: a) 100 Joules b) 2000 Joules c) 20000 Joules d) 6000 Joules e) 5 Joules PHSC 1013 Physical Science Dr. Bullock 27. Its speed at the bottom is of the dive is: a) 10 m/s b) 14.1 m/s c) 20.0 m/s d) 44.7 m/s TEST 3-A e) 55.2 m/s 28. Six balls hang from strings pictured below. How many balls will fly out to the right when the two balls on the left collide at the bottom of their swing? a) none b) one c) two d) three e) four 2m m m m m m 29. A 1000 kg roller coaster starts from rest at the top of a 20 meter hill and slides without friction through the bottom of a curve before rising over a 12 meter hill. What is its kinetic energy at the crest of the second hill? a) 80,000 J b) 78,400 J c) 627,200 J d) 96,000 J e) 108,000 J 30. Momentum depends upon... a) mass and velocity b) mass and acceleration c) force and distance d) mass and distance e) mass and time 31. Starting from rest which car has the high speed at the bottom of the hill? (NOTE: Both masses start from the same height) (mA > mB , B > A ) (a) Block A (b) Block A and Block B have the same speed (c) Block B (d) Need more information (e) none of these mB mA h A B 32. A 1 kg pool ball travels at 10 m/s, East across a pool table and has a perfectly elastic collision with another pool ball of the same mass. At what velocity does the SECOND ball travel after the collision? a) 10 m/s, East b) 10 m/s, West c) 8 m/s, East d) 8 m/s, West e) 0 m/s PHSC 1013 Physical Science Dr. Bullock TEST 3-A 33. A 1 kg pool ball travels at 10 m/s, East across a pool table and has a perfectly elastic collision with another pool ball of the same mass. At what velocity does the FIRST ball travel after the collision? a) 10 m/s, East b) 10 m/s, West c) 8 m/s, East d) 8 m/s, West e) 0 m/s 34. A 100 kg rifle recoils with a speed of 10 m/s when a 100 g bullet is fired from the muzzle. At what speed must the bullet be traveling? a) 370 m/s b) 10 m/s c) 100 m/s d) 1,000 m/s e) 10,000 m/s 35. If the input energy of the above process is 100 J and the output energy is 32 J what is the “Actual Efficiency” of the process? a) 68% b) 132% c) 3.125% d) 32% e) none of these 36. If a push a Big Mac (mass = 0.5 kg) with a force of 2 N a distance of 10 m how much work have I done? a) 50 J b) 5 J c) 20 J d) 1 J e) 10 J 37. How far would I have to push (with a 2 N force) a Big Mac in order to burn to 600 calories (note 600 calories = 2,511,600 J)? a) 1,255,800 m b) 1,200 m c) 300 m d) 5,023,200 m e) 4,186 m 38. Your left hand lifts a 2-N apple by 1.5 m, and your right hand lifts a 4-N grapefruit by 0.5 m. Which hand did the most work? a) Left hand b) Right hand 39. If you triple your altitude above the ground, how is your gravitational potential energy affected? a) no effect b) increases by a factor of three c) decreases by a factor of three d) increases by a factor of nine e) decreases by a factor of nine ** Matching (match the term numbered at left with a definition lettered at right) 40. F= p/t C 41. kg m/s D 42. Ft E 43. heat due to friction A a) exhaust b) Units of work c) Newton’s 2nd Law d) Units of Momentum e) Impulse PHSC 1013 Physical Science Dr. Bullock TEST 3-A ** Matching (match the term numbered at left with the order-of-magnitude estimate lettered at right) 44. Annual US energy use A 45. Human food intake/day D 46. Melting an ice cube C a) 1019 J b) 10-7 J c) 104 J d) 107 J e) 1 J 47. Lifting a baseball two feet E 48. Hop of a flea B ** Specify which type of energy the following terms are associated with ( A-Potential Energy B-Kinetic Energy) 49. Rotational B 50. Nuclear A 51. Chemical A 52. Translational B 53. Gravitational A 54. Thermal B 55. Electromagnetic A 56. Elastic A ** Specify whether the process id reversible or irreversible ( A – reversible B – irreversible) 57. Rotational A 58. Translational A 59. Gravitational A 60. Thermal from friction B 61. Sound B 62. Exhaust B 63. The rate of energy flow is known as a) potential energy b) kinetic energy c) power d) energy transfer e) river energy Dr. Bullock PHSC 1013 Physical Science TEST 3-A 64. The ability to do work is known as a) power b) force c) energy d) mass e) time 65. A block slides on a frictionless, horizontal surface with a speed v until it encounters a spring. The block compresses the spring a certain distance, d. When the spring expands again the block’s speed will be (a) less than v (b) equal to v (c) more than v (d) need more information (e) none of these 66. Suppose rain falls vertically into an open cart rolling along a straight horizontal track with negligible friction. As a result of the accumulating water, which happens? (a) speed decreases, momentum unchanged, and kinetic energy decreases (b) speed decreases, momentum unchanged, and kinetic energy increases (c) speed unchanged, momentum unchanged, and kinetic energy unchanged (d) speed unchanged, momentum decreases, and kinetic energy decreases (e) None of these 67. An object initially at rest breaks into two pieces as the result of an explosion. One piece has four times the kinetic energy of the other piece. What is the ratio of the masses of the two pieces? (a)1/2 (b) 1/4 (c) 1/8 (d) 1/16 (e) none of these 68. A person attempts to knock down a large wooden bowling pin by throwing a ball at it. The person has two balls of equal size and mass, one made of rubber and the other made of putty. The rubber ball bounces back, while the ball of putty sticks to the pin. Which ball is most likely to topple the bowling pin? (a) the rubber ball (b) the ball of putty (c) makes no difference (e)need more information 69. Light carries momentum, so when a beam impinges on a surface, it will exert a force on that surface. If the light is reflected rather than absorbed, the force will be (a) less (b) greater (c) equal either way (d) not enough information (e) none of these 70. Which test do you have? a) A b) B c) C