At mean position, potential energy is minimum and kinetic energy is maximum. Hence,
Umin = 50 J (at mean position)
and Kmax = E – Umin = 200 – 50
Kmax = 150 J (at mean position)
At extreme positions, kinetic energy is zero and potential energy is maximum
∴ Umax = E
Umax = 200 J (at extreme position)