Question

When an air bubble rises in water what happens to its potential energy?

Answer 1

Change in potential energy due to the rise of air bubbles in the water

1. When the bubble rises in a fluid the gravitational potential energy increases as the height increases and there is a net upward force acting on the bubble.
2. The pressure on the bubble also decreases as the bubble rises above the fluid this leads to the expansion of the bubble.
3. Considering the total system of the water and the air bubble at the bottom. When the bubble rises, a corresponding volume of water sinks to the bottom.
4. Hence, the potential energy of the water is increased but that of the bubble is decreased.
5. All systems try to attain their minimum total potential energy. Here also, the total potential energy of the system is reduced with the light air bubble going up and heavier water mass settling down.