Question

Select the correct answer. G = 6.67 × 10-11 N·m2/kg2 Me = 5.598 × 1024 kg What is the velocity of an Earth satellite that is in a circular orbit with a radius of 7.5 × 107 meters measured from the center of the Earth?
A.
2.9 × 103 meters/second
B.
2.3 × 103 meters/second
C.
7.5 × 103 meters/second
D.
5.9 × 103 meters/second

Answer 1

Centripetal force of satellite = gravitational force between earth and the satellite
(m•v^2)/r = (G•Me•m)/r^2
v^2 = (G•Me)/r
v^2 = 6.67x10^-11 x 5.598x10^24 / 7.5x10^7
v = 2231 m/s

so answer is B