Question

The efficiency of a heat engine is $10$. If the heat energy consumed by the engine is $250$KJ, how high would this engine lift an object of mass one kilogram from the ground? (Assume that $g=10m{s}^{-2}$. Remember: w$=$mgh)

Answer 1

Given, H = 250KJ = 250000 J, n = 10,

We know that

$n=\frac{W}{H}\times 100⟹W=\frac{10\times 250000}{100}=25000$

We know that

$W=mgh⟹h=\frac{W}{mg}=\frac{25000}{1\times 10}=2500m$

This engine will lift an object of 1Kg to 2500m high from the ground.