An electric heater supplies heat to a system at a rate of 100 W . If system performs work at a rate

Question

An electric heater supplies heat to a system at a rate of 100 W . If system performs work at a rate of 75 joules per second. Then the rate at which the internal energy increasing is\

Professor PC Thomas Classes · Answer

Heat supplied, $\mathrm{dQ}=100 \mathrm{~W}$ Work done, $\mathrm{dW}=75 \mathrm{~W}$\ From $\mathrm{dQ}=\mathrm{du}+\mathrm{dW}$ $$ \begin{aligned} \mathrm{du} & =\mathrm{dQ}-\mathrm{dW} \ & =100-75 \ & =25 \mathrm{~W} \end{aligned} $$