Answers for Problem Set 14

Last revised 1999/12/03

Chapter 14

HRW pp. 342-348 # 5, 21, 23, 53, 74, 80.

#21.
(a) WMoon = 17 N
(b) r = 2.5 REarth

#23. [Text answer]
(a) Proof
(b) 1.9 h

#53. Proof

#80.
(a) No
(b) Same
(c) Yes

Delta V - Delta K = G M m [ 1/R - 3/(2 r) ], where R is the radius of the Earth and r is the distance of the satellite from the center of the Earth. The altitude of the satellite is r - R. The rotation of the Earth has been neglected.

Chapter 16

HRW pp. 389-398 # 19, 26, 51, 71.

#19.
(a) Proof
(b) m = 12.47 kg
(c) M = 54.43 kg

#26. A = ( mus g / (4 pi2 f2 ) = 3.1 x 10 -2 m

#51.
(a) KEtr = (1/3) k xmax2 = 0.062 J
(b) KErot = (1/6) k xmax2 = 0.031 J
(c) Proof

#71.
(a) 2 pi sqrt [(L2 + 12 x2 )/(12 g x) ]
(b) x/L = 1/sqrt(12)
(c) Proof, but note that x/L = 0.289 . The answer to (b) given in the back of the book is correct for x in this part of the problem.