A linear harmonic oscillator of force constant 2 x 10⁶ N/m and amplitude 0.01 m has a total mechanical energy of 160 joules. Its 

Harmonic oscillator has some initial elastic potential energy and amplitude of harmonic variation of energy is $\frac{1}{2}{\mathrm{Ka}}^2=\frac{1}{2}\times 2\times {10}^6(0.01{)}^2=100\mathrm{J}$
This is the maximum kinetic energy of the oscillator. Thus ${\mathrm{K}}_{max}=100\mathrm{J}$
This energy is added to initial elastic potential energy may give maximum mechanical energy to have value 160J .