The total energy of a particle in linear S.H.M. is 20 J. What is its kinetic energy when its displacment is half of the amplitude ?

Options

A. 10 J
B. 5 J
C. 15 J
D. 25 J

Answer

C

Explanation

`K.E. =(1)/(2)m omega^(2)(A^(2)-x^(2))`
`=(1)/(2)m omega^(2)xx (3)/(4)A^(2)=(3)/(4)((1)/(2)m omega^(2)A^(2))`
`=(3)/(4)E=(3)/(4)xx20=15J`