4.5.5.1.1 - Pressure in a fluid 1

What are fluids?

Anything that can flow

Liquid or gas

What is meant by the ‘ pressure of a fluid’?

The pressure of fluid simply refers to the force that is exerted normal (at right angles) to any surface in contacts with the fluid.

Why do fluids exert pressure on their containers surfaces?

As the particles in a fluid move around, they collude with surfaces and with other particles

These particles then exert a force on the object they collide with

So as pressure is force per unit area , the particles therefore exert a pressure

What is pressure?

Pressure is force per unit area

Give the equation for the pressure at the surface of a fluid.

pressure = force normal to a surface / area of that surface

P = F / a

Give the units of the equation.

pressure - in pascals , Pa

force - in newtons, N

area - in metres squared, m2