Suppose that two heat engines are connected i | vedclass

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(C) Let $Q_h$ be the heat absorbed by the first engine and $Q_m$ be the heat rejected by the first engine,which is absorbed by the second engine. Let

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$\epsilon_{net}=\epsilon_1+ \epsilon_2 - \epsilon_1 \epsilon_2$

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(C) Let $Q_h$ be the heat absorbed by the first engine and $Q_m$ be the heat rejected by the first engine,which is absorbed by the second engine. Let $Q_c$ be the heat rejected by the second engine.Efficiency of the first engine is $\epsilon_1 = \frac{W_1}{Q_h} \implies W_1 = \epsilon_1 Q_h$. The heat rejected is $Q_m = Q_h - W_1 = Q_h(1 - \epsilon_1)$.Efficiency of the second engine is $\epsilon_2 = \frac{W_2}{Q_m} \implies W_2 = \epsilon_2 Q_m = \epsilon_2 Q_h(1 - \epsilon_1)$.The total work done is $W_{net} = W_1 + W_2 = \epsilon_1 Q_h + \epsilon_2 Q_h(1 - \epsilon_1) = Q_h(\epsilon_1 + \epsilon_2 - \epsilon_1 \epsilon_2)$.The net efficiency is $\epsilon_{net} = \frac{W_{net}}{Q_h} = \frac{Q_h(\epsilon_1 + \epsilon_2 - \epsilon_1 \epsilon_2)}{Q_h} = \epsilon_1 + \epsilon_2 - \epsilon_1 \epsilon_2$.

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