Revise GCSE Physics


Question: What is the equation for the energy required to change a materials state?

Energy (J) = mass (kg) x specific latent heat (J/kg).

Energy must be in Joules (J).

Mass must be in kilograms (kg).

Specific latent heat will be in (J/kg)

Examples of Specific Latent Heats:

Material Specific Latent Heat of Fusion (J/kg) Specific Latent Heat of Vaporisation (J/kg)
Water 334,000 2,260,000
Lead 24,500 871,000
Ethanol 108,000 855,000