This time, we start pushing the spring at 0.25 m from the natural length and finish at 0.55 m from the natural length, so the lower limit of the integral is 0.25 and the upper limit is 0.55.

`"Work"=int_0.25^0.55 16x\ dx`

`=[8x^2]_0.25^0.55`

`=1.92\ text[N.m]`

Please support IntMath!