Chapter 8, Problem 3TE

A balloon is weighted so that it is barely able to float in water. If it is pushed beneath the surface, will it rise back to surface, stay at the depth to which it is pushed, or sink? Explain. (Hint: Does the balloon’s density change?)

To determine

Whether the balloon will rise stays at the depth or sink?

Answer to Problem 3TE

The balloon moves back at the surface of the water due to buoyant force on the balloon.

Explanation of Solution

If an object is immersed into the liquid, then liquid exerts a force in the upward direction and equal to the weight of the object. This force is called buoyant force. The force depends on the density of the liquid.

When the balloon is pushed inside the water, then the density of the balloon increases due to an increase in the pressure. The buoyant force on the balloon also increases in the upward direction that pushed the balloon. The balloon rose in an upward direction and reached back at the surface.

Conclusion:

Therefore, the balloon moves back at the surface of water due to buoyant force on the balloon.