Chapter 14, Problem 13STP

To determine

The concept by which a hot air balloon can still float in the air when it is carrying people.

Explanation of Solution

Introduction:

The density of a substance is defined as the ratio of mass to volume of the substance.

  $\text{Density}=\frac{\text{Mass}}{\text{Volume}}$

The things that float on air are less dense than air. Due to low density of gas in balloon, it floats in the air.

In the hot air balloon, there is a burner, which continuously makes inside air of balloon hot and hot air has low density than density of the air. As the result, it willfloat with carrying people also.

Conclusion:

Thus, due to low density of hot air inside hot balloon it floats in the air.