Question

A boy was sitting near a swimming pool.He saw an air bubble coming up to the surface. He noticed that the air bubble was becoming larger in size as moving upwards 1.Which law govern this?​

Answer 1

Answer:

Boyle's law says

PV=RT

Here P is the pressure, V is the volume and T is the remperature. R is a constant. When T is constant

we get

PV=Constant.

When bubble is deep down it has water pressure and atmosphere pressure. As it raises, water pressure which is proportional to the depth, reduces. This will give V more. Volume increases.

Explanation:

Pressure remains equal to the water column above it, that is why bubbles expand. Even though the actual pressure has reduced, the volume increases. A trained scuba diver knows to blow out air as he/she rises and not to pass the bubbles on the way up, because the expanding air can damage lungs, and oxygen in the blood can expand and fill up veins and arteries, causing the “bends.” Bubble air pressure at the surface is the same as air pressure

Answer 2

Hydrodynamics - Boyle's Law

Explanation:

The explanation is that the pressure decreases as the bubble goes up. The volume of gas is inversely proportional to the pressure, pV=K where K is a constant if the temperature and number of molecules is constant.

• But the pressure is equal to $p=p_0+h\rho g$ where $p_0$ is the atmospheric pressure, and h,$\rho$,g are the depth under the water surface, density of water, and the gravitational acceleration, respectively.

• The Hydrostatic Pressure under the water results from the gravitational force acting on the water above the bubble. The numbers work in such a way that 10 meters of depth in water adds the same pressure as the original atmospheric pressure.

• So when a bubble goes up from the 10-meter depth to the surface, the pressure goes down from “2 atmospheres” to “1 atmosphere”, and the volume scales inversely, so the volume of each bubble doubles if the original depth is 10 meters.

If you see comparably dramatic changes of the size of the bubbles at smaller depths, it must be either an illusion or there must be other reasons, like the mergers of many smaller bubbles into bigger ones.