PG. 129-130
13. F = G M m / R2 MJ = 300 ME FJ = 3 FE
FJ = G MJ m / RJ2 = 3 [G ME m / RE2] = 3 FE
FJ = G (300 ME) m / RJ2 = 3 [G ME m / RE2] = 3 FE
G (300 ME) m / RJ2 = 3 [G ME m / RE2]
(300 ME) / RJ2 = 3 [ME / RE2]
(300) / RJ2 = 3 [1 / RE2]
100 / RJ2 = 1 / RE2
RJ2 / 100 = RE2
RJ2 = 100 RE2
RJ = 10 RE
The radius of Jupiter is about ten times as large as the radius of Earth!
20. A rocket going from the Earth to the Moon would require more fuel. Since the Earth has more mass than the Moon, the Earth will exert a larger gravitational force on the rocket than the Moon.
23. The crate lands behind the Porsche, in the direction that the plane was heading
28. a) Show that the monkey will be hit, independent of the dart velocity. (b) Let vd0 be the initial velocity of the dart. Find the dart velocity relative to the monkey at an arbitrary time t during the dart’s flight. In other words, provided the gun is aimed so that the extension of the vector vdg0 passes through the monkey’s position rm0, the dart hits the monkey

Pg.131
10. Distance traveled = circumference of circle = 2 * pi * 3.8 x 108 m = 2.39 x 109 m
Time = 27.3 days = 2.36 x 106 s
Speed = distance / time = 2.39 x 109 m / 2.36 x 106 s = 1010 m/s
This could also be written as 3640