In the above question, find the work done by the spring force as the bloc k is moved leftward from `x_(1)=15mm` to `x_(z)=-10mm`

Explanation

`x_(i)=+15mm`
`x_(f)=-10mm`
`W_(s)=1/2kx_(i)^(2)-1/2kx_(f)^(2)`
`x_(i)=+15min,x_(f)=-10 mm`
`W_(s)=1/2kx_(i)^(2)-1/2kx_(f)^(2)`
`=1/2k(x_(i)^(2)-x_(f)^(2))`
`=1/2xx400xx[(15xx10^(-3))^(2)-(-110xx10^(-3))^(2)]`
`=0.025J`
`=25mJ`