Answer:
The work done by this force can be found via the following formula
[tex]W = \int{F(x)} \, dx = \int\limits^0_{-20} {(-kx)} \, dx = \frac{-kx^2}{2}\left \{ {{x=0} \atop {x=-20}} \right. = \frac{-60*(-20)^2}{2} \\W = -12000J[/tex]
Explanation:
Alternatively, the work done by the object is equal to the elastic potantial energy done by the spring.
[tex]U = \frac{1}{2}kx_2^2 - \frac{1}{2}kx_1^2 =0 - \frac{1}{2}60(-20)^2 = -12000J[/tex]
