Question

The internal energy of a system is increased by 1200 J when 500 J of work is done on the system. How much energy is transferred from the system as heat?

Answer 1

Answer: The internal energy of the system would increase by 21 J.

Explanation: Heat was removed from the system, so Q is negative. Also, work was done on the system. So ΔW is also negative.

Q = ΔU + ΔW

ΔU = Q – ΔW

ΔU = -29 – (-50)

ΔU = 21 J