Page 115 - Schaum's Outline of Theory and Problems of Applied Physics

100 MOMENTUM [CHAP. 8

Answers to Supplementary Problems

8.1. 1500 kg·m/s

8.2. 8800 slug·ft/s

8.3. Yes
8.4. No; no; they can move in any direction provided that the vector sum of their momenta equals the initial momentum
of the first object.
8.5. 18,500 N

8.6. The recoil momenta are the same, but the lighter rifle has a higher recoil velocity.

8.7. (a) The truck’s velocity decreases as rainwater accumulates in it, since the total momentum must remain constant
despite the increase in mass.
(b) The reduced velocity does not change because the water that leaks out carries with it the momentum it had
gained.

8.8. 0.48 m/s

8.9. 5000 kg
8.10. 600 kg/s

8.11. 8 ft/s 2

8.12. 2 m/s

8.13. 0.36 m/s
8.14. (a) 9.09 m/s (b) 1100 J; 1.2%

8.15. (a) 1.82 m/s (b) 88.4 kJ; 96%
8.16. 2.83 ft/s at 28 south of west
◦
8.17. 17 km/h to the northeast

8.18. (a) v = 1.6 m/s, v = 3.6 m/s (b) 0.33 = 33%
2
1
8.19. (a) 138 g (b) 0.75 = 75%
8.20. (a) 6.67 m/s in the same direction as the 5-kg ball (b) 0.78
8.21. 2.3 m/s; 2.8 m/s

8.22. 2.45 m

8.23. 0.58