Chapter 13, Problem 21Q

To determine

To Explain: The moon has practically no atmosphere.

Answer to Problem 21Q

Because of the small size of the moon, it has smaller escape velocity. Due to which the moon has particularly no atmosphere.

Explanation of Solution

Introduction:

Moon has not practically no atmosphere. This concept is explained on the basis of escape velocity. The escape velocity is defined as the minimum speed achieved by the object to get free from the gravitational effect from the Earth’s surface.

The absence of atmosphere on the moon is due to the lower value of the escape velocity of the moon than the earth. Because of the less temperature at the moon, the gas molecules have enough speed to escape the moon’s gravity. That’s the main reason that the atmosphere has evaporated from a long time on Moon.

Conclusion:

Thus, due to lower the escape velocity and because of the small size of the moon, it does not have the atmosphere.