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:
- put the independent variable on the x-axis and the dependent variable on the y-axis
- construct regular scales for the axes
- label the axes appropriately
- plot each point accurately
- 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.
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Sample question 1 - Foundation and Higher
Question
An espresso machine is an electrical appliance. The espresso machine has an electrical heater connected to a 440 V mains supply. The power of the electrical heater is 3.5 kW. Before the espresso machine can be used, its heater must raise the temperature of some cold water.
The specific heat capacity of water is 4,200 J/kg K.
Show that it takes the heater about 90 s to raise the temperature of 1 kg of water from 18掳C to 95掳C. [3 marks]
\(\Delta Q = mc \Delta \theta\)
\(\Delta Q = 1 \times 4,200 \times (95 - 18) = 323,400~J\)
\(t = \frac{E}{P}\)
\(t = \frac{323,400}{3,500} = 92~s\)
Use the formula sheet to find an equation which links energy, mass, specific heat capacity and temperature change. Find the energy required. Recall an equation which links power, energy and time. Use this to find the time. You must give the time to at least 2 sf. Note that the question asks you to show that the time is about 90 s 鈥 you must not use 90 in your calculation 鈥 you should calculate a number close to 90 as the answer.
Sample question 2 - Foundation and Higher
Question
A bubble of gas escapes from a submarine. The volume of the bubble is 23.0 cm3. The pressure of the gas inside the bubble is 297 kPa. The bubbles rise to the surface without changing temperature. Calculate the volume of the bubble when it reaches the surface. Atmospheric pressure = 101 kPa
Use an equation from the formula sheet. [3 marks]
\(p_1 V_1 = p_2 V_2\)
\(297,000 \times 23 = 101,000 \times V_2\)
\(V_2 = \frac{297,000 \times 23}{101,000} = 67.6~cm^3\)
Find the equation from the formula sheet which links pressure and volume of gases. Substitute the numbers and rearrange to find \(V_2\).