Question

Calorific value of wood is 18,000kJ . How much of wood is required to produce heat energy of 108,000kJ ?

Answer 1

The calorific value of wood = 18000
The calorific value of any material is actually the amount of calories or energy generated when per Kg of that material is burnt.

The calorific value of wood is given = 18000 KJ/kg which means 1kg of wood when burnt will give out 180000kj of energy.

Now needed energy is 108000kj.

Hence, the amount of wood that needs to be burnt will be = $\frac{Totalenergyneeded}{Calorificvalue}$
= 108000/18000= 6 kg