Chapter 13, Problem 37A

The weight of an apple near the surface of Earth is 1 N. What is the weight of Earth in the gravitational field of the apple?

To determine

The weight of the Earth in the gravitational field of the apple.

Answer to Problem 37A

The weight of the Earth in the gravitational field of the apple is $1\text{N}$ .

Explanation of Solution

Given:

The weight of the apple is $W=1\text{N}$ in the Earth’s gravitational pull.

Formula used:

According to Newton’s Third Law of Motion,

When an object A apply a force on an object B , then the object B will also exert an equal force on object A .

Calculation:

Consider an apple is placed on the surface of the Earth.

The Earth exerts a gravitational pull on the apple.

The gravitational pull exerted by the Earth on the apple is equal to the weight of the apple $W=1\text{N}$ .

Apply Newton’s Third Law of Motion,

The apple also exerts an equal and opposite force on the Earth.

The apple pulls the Earth towards itself with a force equal to $W=1\text{N}$ .

The Earth and apple acts as a action-reaction pair.

Hence, the weight of the Earth in the gravitational field of the apple is $1\text{N}$ .

Conclusion:

Thus, the weight of the Earth in the gravitational field of the apple is $1\text{N}$ .