If the potential energy of a spring is V on stretching it by 2 cm, then its potential energy when it is stretched by 10 cm will be
V/25
5V
V/5
25V
U=12YALl2 ∴ U∝l2U2U1=l2l12=1022=25⇒U2=25U1
i.e., potential energy of the spring will be 25 V.