For any S.H.M., amplitude is 6 cm. If instantaneous potential energy is half the total energy then distance of particle from its mean position is
3 cm
4.2 cm
5.8 cm
6 cm
If at any instant displacement is y then it is given that
U=12×E ⇒12mω2y2=12×12mω2a2
⇒y=a2=62=4.2 cm