Question

A large stone block is to be part of a harbour wall. The block is supported beneath the surface of the sea by a cable from a crane. Fig 2.1 shows the block with its top face a distance h beneath the surface of the sea. The force acting downwards on the top face of the block, due to the atmosphere and the depth h of water, is 3.5 × 10⁴N. The top of the block has an area of 0.25m². a Calculate the pressure on the top face of the block.

Answer 1

The pressure on the top face of the block can be calculated using the formula:

Pressure = Force / Area

Given that the force acting downwards on the top face of the block is 3.5 × 10⁴N and the area of the top face of the block is 0.25m², we can substitute these values into the formula:

Pressure = (3.5 × 10⁴N) / 0.25m²

Therefore, the pressure on the top face of the block is 1.4 × 10⁵ Pa (Pascal). This is the pressure due to both the atmosphere and the water at depth h.