The pressure experienced by the diver at 10 metres in seawater is greater than atmospheric pressure at sea level because the diver is subjected to the weight of the seawater above them.

Atmospheric pressure is the pressure exerted by the air in the atmosphere. As the diver descends, they are surrounded by an increasing volume of seawater. This seawater has a mass, and the weight of this mass exerts a pressure on the diver.

The pressure exerted by a fluid is directly proportional to its density and the depth. Seawater is denser than air, meaning it has more mass per unit volume. Therefore, the weight of the seawater above the diver is greater than the weight of the air above sea level. This greater weight results in a higher pressure experienced by the diver.

In essence, the pressure at a given depth is the sum of the atmospheric pressure and the pressure due to the weight of the fluid above. Since the diver is at a significant depth, the pressure due to the seawater is substantial and exceeds atmospheric pressure.

The pressure at a given depth in the liquid with a density of 1200 kg/m³ would be greater than the pressure at the same depth in the liquid with a density of 800 kg/m³.

Pressure in a fluid is directly proportional to its density and the depth. This relationship can be expressed as: Pressure = density x gravity x depth.

Since the liquid with a density of 1200 kg/m³ has a higher density than the liquid with a density of 800 kg/m³, and they are at the same depth, the pressure exerted by the denser liquid will be greater. The higher density means that more mass is pressing down on the point at that depth, resulting in a higher pressure. Therefore, the pressure is directly proportional to the density of the liquid.

Given:

• Force (F) = 50 N
• Area (A) = 0.2 m²

Equation:

Pressure (p) = F / A

Calculation:

p = 50 N / 0.2 m² = 250 Pa

Answer: The pressure exerted by the weight on the surface is 250 Pa.