Question

What is the change in internal energy of a system (ΔU) if 53773 J of heat energy is absorbed by the system and 19.5 kJ of work is done on the system (by the surroundings) for a certain process?

Express your final answer in kJ.

Answer 1

Solution.

The first law of thermodynamics:

$\Delta U = Q + A$

$\Delta U = 53773 \ J + 19500 \ J = 73273 \ J$

Answer:

$\Delta U = 73273 \ J$