An astronaut's normal weight it 600 newtons. How much will she weigh while orbiting in a satellite at 12,000 kilometers [two earth radii] above the surface of Earth?
A) zero
B) 67 newtons
C) 300 newtons
D) 200 newtons
E) 150 newtons

Question

Quizplus · Accepted Answer

The gravitational force decreases with the square of the distance from the center of the Earth. At 12,000 km above the surface, the distance is three Earth radii (one Earth radius plus two additional radii). The weight is reduced by a factor of 3^2 = 9, so 600 N / 9 = 67 N.

An Astronaut's Normal Weight It 600 Newtons