Physics - Heat & Thermo Question with Solution | TestHub

Volume decreases during melting of ice so positive work is done on ice water system by atmosphere
Heat absorbed by ice water so $\Delta \mathrm{Q}$ is positive, work done by ice water system is negative
Hence by first law of thermodynamics
$\Delta \mathrm{U}=\Delta \mathrm{Q}+\Delta \mathrm{W}=\text{ Positive }$
So internal energy increases