Answer
$K.E=11J$
Work Step by Step
The maximum kinetic energy is given as:
$K.E_m=\frac{1}{2}mv_m^2$
We also know that
$v_m=x_m\omega$ and $\omega=\sqrt\frac{K}{m}$
Using these two equations, the equation of K.E. can be written as:
$K.E=\frac{1}{2}mx_m^2(\sqrt\frac{K}{m})^2=\frac{1}{2}x_m^2{K}$
We plug in the known values to obtain:
$K.E=\frac{1}{2}(0.30)^2(250)=11J$
