A 150 J of energy added to a system that does 50 J of work, by how much will the internal energy of the system be raised?

GIVEN: Q = 150 J (+ since energy was added to the system)

W = 50 J (+ since work is done by the system)

FIND: ∆U = ?

SOLUTION: ∆U = Q - W

= 150 J - (50 J)

∆U = 100 J

FINAL ANSWER: The internal energy of the system raised 100 J.