A particle of mass 0.1 kg is executing S.H.M. with amplitude 0.1 m. At the mean position its K.E. is `8xx10^(-3)` J. If the intial phase is `45^(@)`. What is the equation of its motion ?

Options

A. `y=0.1 sin(4t)`
B. `y=0.1 sin pit`
C. `y=0.1sin[4t+(pi)/(4)]`
D. `y=0.1sin[4t-(pi)/(4)]`.

Answer

B

Explanation

Here
`(1)/(2)m omega^(2)A^(2)=8xx10^(-3)" J"`
or `(1)/(2)xx(0.1)^(2)xx0.1xx omega^(2)=8xx10^(-3)`
`omega^(2)=16` or `omega=4` rad `s^(-1)`
and `phi=(+pi)/(4)` or `y=0.1sin(4t+(pi)/(4))`.
Correct choice is (b).