Solve Compound Measure Problems

You will need a calculator for this activity!

 

 

In this activity, we are going to solve mixed problems using compound units of measure.

 

Recap on Compound Measure

Speed, density and pressure are all examples of compound measures, which are ones that involve more than one unit of measurement. 

You should know the following formulae and may use the triangles to help you to remember all of them.

 

 

 

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

Work out the density of a piece of wood that has a mass of 24 g and a volume of 12 cm³

 

Answer

First, we find the correct formula.

We want density.

 

 

Substitute the values in:

Density = 24 ÷ 12

Density = 2 g/cm³

 

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.

 

 

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 triangles, just click on the red button and you will be able to see this introduction again.