Chapter 18 - Exercises and Problems - Page 341: 14

Please see the work below.

We know that $\frac{dU}{dt}=\frac{dQ}{dt}+\frac{dW}{dt}$ This can be rearranged as: $\frac{dQ}{dt}=\frac{dU}{dt}-\frac{dW}{dt}$ We plug in the known values to obtain: $\frac{dQ}{dt}=45-165$ $\frac{dQ}{dt}=-120W$