D. Momentum Take-Home Quiz

15.8 points/question (19 questions total)

Just continue on the Scantron sheet we used last week.

 

31.  The area under the curve on a F - t graph represents

    a. impulse.

    b. momentum.

    c. work.

    d. average mass.

 

32.  Momentum is conserved during a completely inelastic collision.

    a. True

    b. False

 

33.  When a cannon fires a cannonball, the cannon will recoil backward because the

    a. energy of the cannonball and cannon is conserved.

    b. momentum of the cannonball and cannon is conserved.

    c. energy of the cannon is greater than the energy of the cannonball.

    d. momentum of the cannon is greater than the energy of the cannonball.

 

 

34.  From the graph, determine the change in momentum of a 100.kg object.

    a. 25.N-s

    b. -25.N-s

    c. 75.N-s

    d. -75.N-s

 

35.  If you pitch a baseball with twice the kinetic energy you gave it in a previous pitch, the magnitude of its momentum is

    a.     the same.

    b.     times as much.

    c.     doubled.

    d.     4 times as much.

 

36.  Car A (mass = 1000 kg) moves to the right along a level, straight road at a speed of 6 m/s.  It collides directly with car B (mass = 200 kg) in a completely inelastic collision.  What is the momentum after the collision if car B was initially at rest?

    a. Zero

    b. 6.KN-s to the right.

    c. 2. KN-s to the right.

    d. 10. KN-s to the right.

    e. None of the other choices is correct.

 

37.  In the previous problem, what is the speed of the car immediately after the collision?

    a. zero

    b. 3.m/s

    c. 4.m/s

    d. 5.m/s

 

38.  A proton, of mass m and speed v, strikes an alpha-particle (which consists of 2 protons and 2 neutrons) at rest.  If the collision is completely elastic, what speed will the alpha-particle have after the collision?  (Assume the neutron's mass equals the proton's mass.)  (Hint:  Use equations 6.15 and 6/16 on p. 191 of your textbook)

    a. Zero

    b. 2/3 v

    c. 2/5 v

    d. 5/3 v

 

 

39.  An Olympic diver dives off the high-diving platform.  The magnitude of his momentum will be a maximum at point

    a. A.

    b. B.

    c. C.

    d. D.

 

40. Consider the diver described in the previous problem.  After leaving the platform, the diver's momentum will be least at point:

    a. A

    b. B

    c. C

 

41. A ball, of mass 100 g, is dropped from a height of 12 m.  Its momentum when it strikes the ground is, in kgúm/s,

    a. 1.5

    b. 1.8

    c. 2.4

    d. 4.8

 

42. A 60.gram toy rocket achieves a speed of 80.m/s after 3.0 s, when fired straight up.  What is the average total force on the rocket during the 3 s?

    a. 1.2 N

    b. 1.6 N

    c. 2.2 N

    d. 3.4 N

 

43. A sailboat of mass m is moving with a momentum p.  Which of the following represents its kinetic energy?  (Hint:  Look in your class notes.  I did define how KE and P were related algebraically)

    a. p2/2m

    b. 1/2 mp2

    c. mp

    d. mp/2

 

44. Automobile air bags reduce what during a collision?

    a. the momentum exerted upon the passenger

    b. the forces exerted upon the passenger

    c. the kinetic energy transferred to the passenger

    d. speed of the automobile

 

45. In an inelastic collision, the final total momentum is

    a. less than the initial momentum

    b. more than the initial momentum

    c. the same as the initial momentum

    d. none of these

 

46. Suppose a bug spatters upon your windshield as you drive down the road.  Which sustains the greater change of momentum?

    a. the car

    b. the bug

    c. both the same

    d. insufficient information

 

47. Which of the following has units of momentum?

    a. kg-s/m

    b. kg-m2/s

    c. kg-m2/s2

    d. J-s/m

    e. N-m

 

48. Two cars suffer a head-on collision. What is conserved in the collision? (Hint:  Mechanical energy is but one form of energy.  Don't forget heat, sound and light energy.  Each form of energy can be converted into another type - so long as total energy is conserved.  Ever "heard" a crash?)

    a. kinetic energy

    b. mechanical energy and momentum

    c. momentum

    d. none of these

 

49. In an inelastic collision, the initial kinetic energy is less than the final kinetic energy.

    a. True

    b. False