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, ΔU (in kJ) is : 

(1) 12 

(2) –8 

(3) 8 

(4) –12

Answer 1

Correct option (3) 8

Explanation:

Work done on system = +10 kT

Heat escaped = –2kI 

ΔU = q + w

= 10 – 2 = 8 KJ