Chapter 4, Problem 55A

To determine

To Explain:Rock is accelerating towards the earth but earth does not accelerate towards rock.

Explanation of Solution

Introduction:

Earth accelerates every falling object towards itself by the force of gravity. Here, action and reaction take place according to Newton's third law of motion which states that to every action there is a reaction, which is equal to it and in opposite direction.

Earth accelerates the rock towards itself this is action. Also,earth isaccelerated towards object but this force is negligible since earth's mass is large.

The acceleration of earth is given by,

  $a_e=\frac{F}{m_e}$

Here, earth accelerates the rock by the force of gravity.