Answer
The kinetic energy is $~~12~J$
Work Step by Step
We can find the kinetic energy $K_2$:
$K_2+U_{e2} = K_1+U_{e1}+W$
$K_2+0 = 0+U_{e1}+W$
$K_2 = \frac{1}{2}k~x_1^2-F~\Delta x$
$K_2 = \frac{1}{2}(4000~N/m)~(0.10~m)^2-(80~N)(0.10~m)$
$K_2 = 12~J$
The kinetic energy is $~~12~J$
