Starting from the origin a body osillates simple harmonicall with a period of 2 s. A fter what time will its kinetic energy be 75% of the total energy?

Options

A. 1/12 s
B. 1/6 s
C. 1/4 s
D. 1/3 s

Answer

D

Explanation

`(1)/(2) mv^(2) = (75)/(100) xx (1)/(2) m (A omega)^(2)`
`v = (sqrt(3))/(2) A omega`
`A omega sin omega t = (sqrt(3))/(2) A omega rArr omega t = (pi)/(3)`
`t = ((pi)/(3))/((2pi)/(2)) = (1)/(3) s`