A student submerges a small stone in a tank of seawater. The stone sinks to the bottom of the tank. Explain why the pressure acting on the stone increases as it sinks deeper into the seawater.

Pressure in a liquid increases with depth because the weight of the liquid column above the stone increases as it sinks.

The pressure at a depth h is given by p=ρgh, so a greater depth means a larger ρgh.

Seawater has a higher density than fresh water, so the same depth gives a higher pressure.

The pressure acts equally in all directions on the stone, so the upward buoyant force is balanced by the downward weight of the stone.