The total energy of the body executing S.H.M. is E. Then the kinetic energy when the displacement is half of the amplitude, is
[RPMT 1994, 96; CBSE PMT 1995; JIPMER 2002]
Total energy in SHM E = 12mω2a2 : ( where a = amplitude )
Potential energy
U = 12mω2(a2−y2)=E−12mω2y2
When y = a2⇒U=E−12mω2(a24)=E−E4=3E4