Q.

The maximum potential energy of a block executing simple harmonic motion is 25 J. A is the amplitude of oscillation. At A2, the kinetic energy of the block is      [2023]

1 37.5 J  
2 9.75 J  
3 18.75 J  
4 12.5 J  

Ans.

(3)

umax=12mω2A2=25 J

KE at A2=12mv12=12mω2(A2-A24)

KE=12mω23A24=34(12mω2A2)

KE=34×25=18.75 J