Question

A heart engine takes in 320 j of energy from a hot reservoir and performs 25.0 J of work in each cycle.find

(I). The efficiency of the engine and

(ii). The energy expelled to the cold reservoir in each cycle.

Answer 1

Given:

$Q_1=\rm 320\: J$

$W=\rm 25.0\: J$

(i) The efficiency of the engine

$$\eta=\frac{W}{Q_1}=\frac{25.0}{320}=0.078=7.8\%$$

(ii) The energy expelled to the cold reservoir in each cycle

$$Q_2=Q_1-W=320-25.0=295\:\rm J$$