I am lost with this problem.

**A bottle containig air is closed with a watertight yet smoothly moving piston. The bottle with its air has a total mass of 0.30kg. At the surface of a body of water whose temperature is a uniform 285 K throughout, the volume of air contained in the bottle is 1.5L.**

Recall that the pressure of water increases with depth below the surface, D, as p=po+ρ *g*D, where po is the surface pressure and ρ=1.0 kg/L.

The bottle is submerged.

a- What is the volume of the air in the bottle as a function of depth?

b- Calculate the buoyant force on the bottle as a function of depth?

Recall that the pressure of water increases with depth below the surface, D, as p=po+ρ *g*D, where po is the surface pressure and ρ=1.0 kg/L.

The bottle is submerged.

a- What is the volume of the air in the bottle as a function of depth?

b- Calculate the buoyant force on the bottle as a function of depth?

There are other questions but I need to understand thoses first.

B