A system absorbs 21.6 kJ of heat while performing 6.9 kJ of work on the surroundings. If the initial internal energy, U, is 61.2 kJ, what is the final value of U?

Question

Quizplus · Accepted Answer

The final value of U can be found using the First Law of Thermodynamics: ΔU = Q - W, where ΔU is the change in internal energy, Q is the heat absorbed, and W is the work done. Plugging in the given values, we get:
ΔU = 21.6 kJ - 6.9 kJ = 14.7 kJ
The final value of U is then:
Ufinal = Uinitial + ΔU = 61.2 kJ + 14.7 kJ = 75.9 kJ
Therefore, the correct answer is D.

A System Absorbs 21