Question

A heavy weight is suspended from a spring Te energy stored in the spring is E. If the weight is raised till the spring comes to its stretched position and the work done in doing so be W. then gain in gravitational potential energy of the weight will be : 

(A) W + E 

(B) W – E 

(C) W

(D) E

Answer 1

Answer is (A) W + E

Gain in gravitational potential energy = work done + energy lost by the spring.