When a long spring is stretched by 1 cm, the potential energy stored in the spring is U. What will be the potential energy stored in it if it is stretched by 4 cm ?

Options

A. 4 U
B. 9 U
C. 16 U
D. 25 U

Answer

C

Explanation

`P.E.=U=(1)/(2)Kx^(2) therefore (U_(2))/(U_(1))=(x_(2)^(2))/(x_(1)^(2))=(4^(2))/(1^(2))=16`