Answer:
1000 kJ of heat energy is required.
Explanation:
Heat energy required, H = mcΔT, where m is the mass, C is specific heat and ΔT is change in temperature.
Mass of coal, m = 5 kg
Change in temperature, ΔT = 220-20 = 200°C
Specific heat of coal = 1 kJ kg⁻¹°C⁻¹
Substituting
H = mcΔT = 5 x 1 x 200 = 1000 kJ
1000 kJ of heat energy is required.
