Question

A given mass of fuel having a calorific value of 45,000 kJ/kg on burning produces 67,500 kJ of heat. The mass of the fuel used is:

• A. 2 kg
• B. 1.5 kg
• C. 5 kg
• D. 15 kg

Answer 1

The correct option is B 1.5 kg

Heat produced on burning fuel = 67,500 kJ
Calorific value of fuel = 45,000 kJ/kg
Mass of fuel = ?

We know, $Calorificvalue\left(kJ/kg\right)=\frac{Amountofheatproduced\left(kJ\right)}{Massoffuel\left(kg\right)}$
$Massoffuel=\frac{Amountofheatproduced}{Calorificvalue}$ $=\frac{67,500kJ}{45,000kJ/kg}=1.5kg$