Posted in Physics Revision


P3 3.5


Definition: the force exerted divided by the area on which it is exerted → measured in Pascals (Pa).

So,pressure = force over area.png

We know that force is measured in Newtons, and area is measured in metres squared. So pressure is measured in newtons per metre squared. This is a unit called Pascals.


We can use the equations to conclude that a wider area means there is less force exerted per metre squared → a wider area = less pressure. This provides an explanation as to why flat shoes don’t sink as easily in mud as high heels.

The atmospheric pressure on earth is 100 000 Pa.

Pressure in Liquids

We describe liquids as being virtually incompressible. This is because there are no gaps and no space between the liquid molecules.

pressure in liquids.png

The pressure exerted by the liquid (shown in red) is the same in all directions.


[as year 11s I am sure you are familiar with the sensation of pressure. you’ll be fine]

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s