Question

Calculate the amount of fuel required to produce 360000 kJ of heat. Calorific value of the fuel is 9000 kJ/kg.

Answer 1

Calorific value =$\frac{\mathrm{Heat}\mathrm{energy}\mathrm{produced}\mathrm{by}\mathrm{fuel}}{\mathrm{Amount}\mathrm{of}\mathrm{fuel}\mathrm{used}}$

Amount of fuel = $\frac{\mathrm{Heat}\mathrm{energy}\mathrm{produced}\mathrm{by}\mathrm{fuel}}{\mathrm{Calorific}\mathrm{value}}$

= $\frac{360000\mathrm{kJ}}{9000\mathrm{kJ}/\mathrm{kg}}$

= 40 kg

40 kilograms of fuel is needed to produce heat energy of 360000 kJ.