Before firing, a ceramic kiln shelf is warmed by an electric heating element. A joulemeter records an energy transfer of 48000 J. Tests show that the kiln walls and the air receive 40% of this energy. The temperature of the shelf increases by 30 ∘C30\ ^\circ\mathrm{C}30 ∘C without a change of state. The specific heat capacity of the shelf is 800 J kg−1 ∘C−1800\ \mathrm{J\,kg^{-1}\,{}^\circ C^{-1}}800 Jkg−1∘C−1. What is the mass of the shelf? Use ΔQ=mcΔθ\Delta Q=mc\Delta\thetaΔQ=mcΔθ.
0.80 kg0.80\ \mathrm{kg}0.80 kg
2.00 kg2.00\ \mathrm{kg}2.00 kg
3.33 kg3.33\ \mathrm{kg}3.33 kg
1.20 kg1.20\ \mathrm{kg}1.20 kg
110 exam-style questions on Edexcel GCSE Physics 14.2 Specific heat capacity and latent heat, covering 14.2.1 Heating, temperature and changes of state, 14.2.2 Specific heat capacity and specific latent heat, 14.2.3 Specific heat capacity calculation, 14.2.4 Specific latent heat calculation, and 14.2.5 Reducing energy transfer through thermal insulation. Each one has a worked solution and a mark scheme showing where the marks go.