You will need a calculator for this activity!
Like speed and density, pressure is another example of a compound measure, which is one that involves more than one unit of measurement.
Pressure is a measure of how much force (Newtons) is acted upon an area (e.g. cm2 , m2) and can be measured in N/cm2 or N/m2 etc......
Like speed and density, you should know the following formulae and may use the triangle to help you remember the three pressure, force and area formulae.
We will be given two of the three compound measures, so it is only a matter of substituting the values given into the correct formula!
Let's look at a couple of typical questions!
Example 1
A vase of flowers is placed upon a table and exerts a force of 300 N on an area of 15 cm2
Work out the pressure.
Answer
First, we find the correct formula.
We want Pressure = Force ÷ Area
Substitute the values in:
Pressure = 300 ÷ 15
Pressure = 20 N/cm2
Let's try another one!
Example 2
A pressure of 100 N/cm2 is exerted on an area of 12 cm2
Work out the force.
Answer
First, we find the correct formula.
We want Force = Pressure x Area
Substitute the values in:
Force = 100 x 12
Force = 1,200 N
Let's have a go at some questions now.
If you need to remind yourself of the formulae or have another look at the triangle, just click on the red button and you will be able to see this introduction again.