Question

The variation of potential energy of harmonic oscillator is as shown in figure. The spring constant is N/m.

Answer 1

Total potential energy = 0.04 J
Resting potential energy = 0.01 J
Maximum kinetic energy = (0.04 - 0.01) = 0.03 J, which should be equal to $\frac{1}{2}m{\omega }^2{a}^{2}or\frac{1}{2}k{a}^2$.
$0.03=\frac{1}{2}k\times {\left(\frac{20}{1000}\right)}^2$$k=0.06\times 2500N/m=150N/m$