Answers to even questions in Chapter 6.   Notify me of any disagreement.

2.  a) The momentum of the proton is 8.35*10^(-21) kg m/s.
    b) The momentum of the bullet is 4.50 kg m/s.
    c) The momentum of the sprinter is 750 kg m/s.
    d) the momentum of the earth is kg 1.78*10^(29) m/s.

4.  a) The baseball's speed must be 31.0 m/s.
    b) The bullet has the greater kinetic energy (by a factor of 48.4).

6.  The magnitude of the linear impulse is 364 kg m/s,
    and the magnitude of the average force is 438 N.

8.  a) The impulse of the force is 8.0 N s.
    b) The final velocity of the mass initially at rest is 5.3 m/s.
    c) The final velocity if initially moving at - 2.0 m/s is 3.3 m/s.

10. a) The impulse for the first 3 seconds is 12.0 kg m/s.
    b) The impulse for the whole 5 seconds is 8.0 kg m/s.
    c) At t=3.0 s the speed is 8.0 m/s;  at t=5.0 s the speed is 5.3 m/s.

12. a) The velocity at the end of the 1.50 s interval is 9.0 m/s.
    b) The velocity at the end of a further 3.0 s is -15 m/s.

14. The average force exerted on the ball is 260 N away from wall.

16. The speed of the golf ball just after impact is 65 m/s.

18. a) The girl's velocity relative to the ice surface is 1.15 m/s.
    b) The velocity of the plank relative to the ice surface is -0.346 m/s.

20. a) The speed of the earth just before impact is 9.0*10^(-24) m/s.
    b) The ball velocity is much greater than that of the earth.

22. The mass of the second sphere is 6.00 kg.

24. The initial speed of the bullet is 528 m/s.

26. The initial speed of the bullet is 142.9 m/s.

28. a) The final velocity of the three cars is +2.2 m/s.
    b) No.

30. The velocities are -40.0 cm/s (10.0-g) and 10.0 cm/s (15.0-g).

32. a) The speed of the first ball is 0.00 m/s & of the second ball, 1.50 m/s.
    b) The speed of the first ball is -1.00 m/s & of the second ball, 1.50 m/s.
    c) The speed of the first ball is 1.00 m/s & of the second ball, 1.50 m/s.

34. a) The velocity of the 10.0-kg mass after the collision is 12.42 m/s, 
       at an angle of 14.9 degrees north of east.
    b) The amount of the initial kinetic energy lost in the collision is 7.2%.

36. a) The velocity of the 0.30-kg puck after the collision is 1.1 m/s
       at an angle of 29.7 degrees with respect to the x-axis.
    b) The amount of the initial kinetic energy lost in the collision is 32%.

38. The average force on the particle during the first 3 seconds is 2.67 N.

40. It takes the astronaut 240 seconds to reach his ship.

42. The ratio of the total kinetic energy after the collision to the kinetic 
    energy before the collision is 0.398%.  Friction accounts for the remainder.

44. The average force exerted on the man by the water is 1.1*10^3 N.

46. a) Before the collision, v_1 is 9.90 m/s and v_2 is -9.90 m/s.
    b) After the collision, v_1 is -16.5 m/s and v_2 is 3.30 m/s.
    c) m_1 rises to a height of 13.9 m, m_2 to a height of 0.56 m.

48. The initial speed of the bullet is 340 m/s.

50. a) The velocity of the carts after collision is 0 (red) and 3.0 (blue) m/s.
    b) The maximum compression of the spring is 0.21 m.

52. After 3 seconds the scale reads 23 N.

54. The coefficient of kinetic friction is 0.410.

56. a) The final speeds are sqrt(2)*v_0 m/s and sqrt(2/3)*v_0 m/s respectively.
    b) The 3m mass is scattered at an angle of 35.3 degrees.

58. a) 28% of the neutron's kinetic energy is transferred to the carbon nucleus.
    b) After the collision, KE_neutron is 1.2*10^(-13) J 
       and KE_carbon is 4.534*10^(-14) J.

60. The second block moves a distance (2*v_0^(2)/(mu*g)-4*d)/9 before stopping.