An air source heat pump transfers energy from the air outside a building to increase the temperature of the air inside the building - AQA - GCSE Physics Combined Science - Question 6 - 2021 - Paper 1

The energy needed to change the state of the liquid coolant is called the latent heat of vaporisation.

The mass of the coolant stays the same as it evaporates to become a vapour.

The pressure in the pipe increases because the compressor increases the density and temperature of the coolant vapour. This leads to more collisions per second among the particles, resulting in a greater force per collision, which increases the pressure.

To calculate the specific heat capacity (c) of the air:

1. Total energy input = 1560 kJ

2. Useful output energy = total energy input * efficiency = 1560 kJ * 0.875 = 1365 kJ

3. Temperature change = 22.1°C - 11.6°C = 10.5°C

4. Using the formula:

   $c = \frac{Useful \ output \ energy}{mass \times temperature \ change}$

   $c = \frac{1365 \times 10^3 J}{125 kg \times 10.5 °C}$

   After calculation, c = 1040 J/kg°C in standard form.

The advertisement is incorrect because it suggests that the total energy input is greater than the energy supplied from electricity. It implies an efficiency greater than 100%, which is not possible, as the efficiency can never exceed 100%. The efficiency cannot be more than what is input into the system.