Question

Calorific value of wood is 18000 kj/kg.how much wood is required to produce heat energy of 108000 kj/kg

Answer 1

Calorific val. Of wood =18000kj/kg.
Therefore, wood req. To produce 108000kj of heat =
108000/18000= 6kg of wood.

Answer 2

ANSWER:

6 kgs of wood is required to produce heat energy of 108000 kj/kg.

EXPLANATION:

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 in as 18000 kilo joule per kg that means 1 kg of wood when burnt will give out 18000 kilojoules of energy.

Now the needed energy is 108000 kilojoules hence the amount of word that needs to be burnt will be  

$\bold{\frac{\text {total energy needed}}{\text {calorific value}}=\frac{108000}{18000}=6 \mathrm{kgs}}$