An object of weight W is in freefall close to the surface of Earth.The magnitude of the force that the object exerts on Earth is
A)greater than W.
B)less than W.
C)equal to W.
D)zero.
E)cannot be determined without knowing the relative masses of the object and the earth.

Question

Quizplus · Accepted Answer

According to Newton's third law of motion, every action has an equal and opposite reaction. Therefore, the object exerts a force on Earth that is equal in magnitude but opposite in direction to the force that Earth exerts on the object. This force is known as the weight of the object and has a magnitude of W. Therefore, the magnitude of the force that the object exerts on Earth is also W.

An Object of Weight W Is in Freefall Close to the Surface