Question

How much pressure need to release dams

Answer 1

Answer:

Explanation:

l

Background – pressure and force

Pressure is the total force acting on a given area. It has units of Nm−2, or uses the derived unit

of the pascal, Pa. The pressure is a static fluid at a depth h below the surface is given by the

expression

p = ρgh,

where ρ is the density of the fluid, g is the acceleration due to gravity and h is the depth below

the surface. As pressure is a measure of the total force acting on a given area, and in the above,

the force derives from the weight of the fluid, it makes sense that the pressure increases with

depth as there’s more mass of water above the point of measurement.

Look at the diagram in Figure 1 which shows a schematic of a body of water that is being

retained by a dam wall.

As h2 > h1

, it is obvious that p2 > p1

. This means that the force acting on a small area near the

top of the area is smaller than the force acting on a small area near the bottom. However,

because the pressure changes linearly with depth, which means the force acting on each small

area also changes linearly with depth, the average pressure over A, given by ( 1