Question

A non-flow system receives 80 kJ of heat transfer and loses 20 kJ as work transfer. What is the change in the internal energy of the fluid?

Answer 1

By applying the first law of thermodynamics to the given non-flow system;

Q=∆U-W

Given;

W=20kJ

Q=80kJ

Q=∆U-W

Thus; ∆U=Q-W

=(80-20)kJ

=60kJ.