Physics

Problem

Identify the correct expression for the elastic potential energy

U

stored in a spring of force constant

k

when it is compressed by a distance

x

from its natural length. a)

U = kx^{2}

U = -\dfrac{1}{2} k x^{2}

U = \dfrac{1}{2} k x^{2}

U = \dfrac{1}{4} k x^{2}