In an experiment 4.5kg of fuel was completely burnt. The heat produced was measured to be 180,000kg. What is the calorific value of the fuel?
I assume that the heat produced is 180,000 Joules and not kilograms, since Joules is the unit for energy
Calorific value = Heat energy Produced/Mass of fuel
= 180,000/4.5
= 40,000 J/kg