Chapter 7, Problem 7TE

The Earth and the Moon are attracted to each other by gravitational force. Does the more massive Earth attract the less massive Moon with a force that is greater, smaller, or the same as the force with which the Moon attracts the Earth?

To determine

Whether the more massive Earth attracts the less massive Moon with the force greater, smaller, or same as the force Moon attracts the Earth.

Answer to Problem 7TE

The Earth attracts the less massive Moon by greater force than the force by which the Moon attracts the earth.

Explanation of Solution

The Earth and Moon attracted each other by the gravitational force that depends on the mass of Earth and Moon, and the distance between the Earth and Moon. The distance between the Earth and the Moon almost remains the same.

If the Earth becomes more massive and Moon becomes less massive, then the variation in the gravitational force between them depends on either the increase in the mass of the Earth or decrease in the mass of the Moon. If the increase in the mass of the Earth is the same as the decrease in the mass of the Moon, then the gravitational force will remain the same.

If the increase in the mass of the Earth is very large compared to a decrease in the mass of the Moon, then the gravitational force of the Earth becomes higher than the gravitational force of the Moon on the Earth. The Earth attracts the less massive Moon by a greater force than the Moon attracts the Earth.

Conclusion:

Therefore, the Earth attracts the less massive Moon by greater force than the force by which the Moon attracts the earth.