Question

A steam engine delivers 5.4×10⁸ J of work per minute and services 3.6 × 10⁹ J of heat per minute from its boiler. What is the efficiency of the engine? How much heat is wasted per minute? 

Answer 1

Work done by the steam engine per minute, W = 5.4 × 10⁸ J

Heat supplied from the boiler, H = 3.6 × 10⁹ J

Hence, the percentage efficiency of the engine is 15 %

Amount of heat wasted = 3.6 × 10⁹ – 5.4 × 10⁸ 

= 30.6 × 10⁸ = 3.06 × 10⁹ J

Therefore, the amount of heat wasted per minute is 3.06 × 10⁹ J.