Question

600 J of work is done on a system in a process that decreases the thermal energy of the system by 300 J.

Answer 1

Answer:

900 J

Explanation:

$\Delta U$ = Change in entropy = -300 J (Decrease)

$W$ = Work done = 600 J

$Q$ = Heat transferred

Change in internal energy is given by

$\Delta U=W+Q\\\Rightarrow Q=\Delta U-W\\\Rightarrow Q=-300-600\\\Rightarrow Q=-900\ J$

The heat transferred to or from the system as heat is -900 J.

900 J is transferred. As heat is transferred from the system the sign is negative.