http://www.ck12.org Chapter 7. Centripetal Forces Version 2
Answers to Selected Problems
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5. a. 100 N b. 10 m/s^2
6. a. 25 N towards her b. 25 N towards you
7. a. 14.2 m/s^2 b. 7. 1 × 103 N c. friction between the tires and the road
8..0034g
9. a. 6. 2 × 105 m/s^2 b. The same as a.
10. 3. 56 × 1022 N
11. 4. 2 × 10 −^7 N; very small force
12.g= 9 .8 m/s^2 ; you’ll get close to this number but not exactly due to some other small effects
13. a. 4× 1026 N b. gravity c. 2× 1041 kg
14..006 m/s^2
15. a..765 b. 4880 N
16. a.∼ 10 −^8 N very small force b. Your pencil does not accelerate toward you because the frictional force on
your pencil is much greater than this force.
17. a. 4. 23 × 107 m b. 6. 6 Red. The same, the radius is independent of mass
18. 1. 9 × 107 m
19. You get two answers forr, one is outside of the two stars one is between them, that’s the one you want,
- 32 × 1010 m from the larger star.
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21.. - a.v=28 m/s b.v−down,a−right c.f−right d. Yes, 640N