What work is required to stretch a spring of spring constant 30 N/m from x=0.25m to x=0.30m

Question

What work is required to stretch a spring of spring constant 30 N/m from x=0.25m to x=0.30m

Answer 1

The work will be equal to the difference in spring potential energies at the two stretch lengths.

U = (1/2)*k*x²

U2 - U1 = W

1.35J - 0.9375J = 0.4125J