# Forces and their effects - Maths questions

Maths questions often start with the command words 'calculate' or 'determine'. They will then have a blank space for you to show your working. It is important that you show your working, don't just write the answer down. You might earn marks for your working even if you get the answer incorrect.

Some maths questions might ask you to 'show that' something is true. These questions often require you to prove something mathematically. For example, you might have to calculate two values and then compare them.

In some maths questions you will be required to give the units. This may earn you an additional mark. Don't forget to check whether you need to do this.

Maths questions might include graphs and tables as well as calculations. Don't forget to take a ruler and calculator.

If drawing graphs, make sure you:

1. put the independent variable on the x-axis and the dependent variable on the y-axis
2. construct regular scales for the axes
3. label the axes appropriately
4. plot each point accurately
5. draw a straight or curved line of best fit (you can use a special best fit line ruler to help with this)

If you are asked to calculate an answer and it has lots of significant figures, you should try to round it to the same number of significant figures you were given in the data in the question. Don't forget to check your rounding.

Edexcel questions courtesy of Pearson Education Ltd.

## Sample question 1 - Foundation and Higher

Question

When underwater, a diver tries to move a large stone block. The diver uses a long iron bar and a pivot, as shown in Figure 1. When pushing down with a force of 120 N, the block is balanced.

Calculate the size of the force, F, of the bar on the block. [3 marks]

Recall the equation: moment = force × distance

Calculate sum of anticlockwise moments = 120 × 1.3 = 156 Nm

Calculate sum of clockwise moments = 156 Nm = F × 0.4

F = 156 ÷ 0.4

So F = 390 N

## Sample question 2 - Foundation and Higher

Question

The diagram in Figure 1 shows the apparatus used to investigate moments. The 2 N weight is placed 60 cm from the pivot. The newtonmeter is placed 10 cm from the pivot.

Calculate the reading on the newtonmeter. Ignore the weight of the ruler. [3 marks]

Recall the equation: moment = force × distance

Calculate sum of clockwise moments = 2 × 0.6 = 1.2 Nm

Calculate sum of clockwise moments = 1.2 Nm = F × 0.1

F = 1.2 ÷ 0.1

So F = 12 N