Question

What is the change in internal energy if 70 J of heat is added to a system and

the system does 30 J of work on the surroundings? Use AU = Q-W.
A. -40 J
B. -100 J
C. 100 J
O D. 40 J

Answer 1

Change in internal energy AU = 40 J

Step-by-step explanation:

Given:

Amount of heat added = 70 J

Work done = 30 J

Find:

Change in internal energy AU

Computation:

The net thermal conductivity into a process less the net work performed by the system represents the shift in internal energy.

Change in internal energy AU = Q - W

Change in internal energy AU = 70 J - 30J

Change in internal energy AU = 40 J