A particle is executing linear SHM. The average kinetic energy and average potential energy, over a period of oscillation, respectively are Kav and Uav. Then,
Kav = Uav2
Uav = Kav2
Kav = Uav
Uav = Kav3
K = 12mv2 = 12mA2ω2cos2ωt
Average value of cos2 ωt is 12 over one cycle
∴ Kav = 14mω2A2------------(i)
U = 12mω2x2 = 12mω2A2sin2ωt
Average value of sin2 ωt is 12 over one cycle.
∴ Uav = 14mω2A2 ---------(iii)
From Eqs. (i) and (ii), we get Kav = Uav