A system does 210 J of work on its environment and gains 80.6 J of heat in the process. Find the change in the internal energy of (a) the system and (b) the environment.

Question

I am not sure how to start this. Thank you for the help.

Answer 1

ΔU = Q - W
Where ΔU is the change in the internal energy of the system,
Q is the heat/energy gained from the surroundings,
W is the work done on the environment.

ΔU =80.6-210=-129.4 J.
The internal energy decreased by 129.4 Joules which corresponds to a temperature decrease of the system