During a process, system absorbs $710 \mathrm{~J}$ of heat and increases the internal energy by $460…
During a process, system absorbs $710 \mathrm{~J}$ of heat and increases the internal energy by $460 \mathrm{~J}$. What is the work performed by system?
-250 J
-1170 J
-710 J
-460 J
Solution
$\begin{aligned}
& \mathrm{q}=+710 \mathrm{~J} \\
& \Delta \mathrm{U}=460 \mathrm{~J}
\end{aligned}$
From Ist law of thermodynamics,
$\begin{aligned}
& \Delta \mathrm{U}=\mathrm{q}+\mathrm{w} \\
& 460=710+\mathrm{w} \\
& \mathrm{w}=460-710 \\
& =-250 \mathrm{~J}
\end{aligned}$