Chapter 13, Problem 106A

To determine

To Explain: The reason for the air in a balloon must be hotter to lift the same number of people at different altitude.

Explanation of Solution

Introduction:

The atmosphere becomes thin when at higher altitudes, which means its density reduces.

After the gas is pushed out from the bottom of the balloon, the air inside the balloon will be lighter than outside, that means the density is increasing. The temperature of the air regulates the lifting power. When someone inside the balloon heats the gas, the gas inside the balloon becomes lighter than the air outside the balloon. That hot air causes a rise in the balloon.

Now, the air inside it has to be hotter.

Conclusion:

Hence, the air in a balloon would have to be hotter to lift the same number of people at different altitudedue to less density of the atmosphere.