devarshi-dt-logo

Question:

During compression of a spring, the work done is 10 kJ and 2 kJ escaped to the surroundings as heat. The change in internal energy, U (in kJ) is:

8

-8

12

-12

Solution:

Correct option is A. 8
According to question, q = -2 kJ and W = 10 kJ
Now, ΔU = q + w
ΔU = -2 + 10 = 8 kJ