A woman who normally weighs 400 N stands on top of a very tall ladder so she is one Earth-radius above Earth's surface.What is her weight there?

Question

Quizplus · Accepted Answer

When the woman is on top of a very tall ladder, she is one Earth-radius above Earth's surface. At that height, the gravitational force acting on her decreases because she is farther away from the center of the Earth. Therefore, her weight is less than her usual weight of 400 N. According to the inverse square law of gravity, the weight of an object decreases with the square of the distance from the center of the Earth. Since the woman is one Earth-radius away from the center of the Earth, which is the same as the distance from the center of the Earth to the surface of the Earth, her weight is 1/4 of her usual weight or 100 N. Therefore, the best choice is B) 100 N.

A Woman Who Normally Weighs 400 N Stands on Top