The displacement of a particle executing SHM is given by.
`y=5 sin(4t+pi/3)` If T is the time period and the mass of the particle is 2 g, the kinetic energy of the particle when `t=T/4` is given by,

Options

A. 0.4 j
B. 0.5 j
C. 3 j
D. 0.3 j

Answer

D

Explanation

`y=5 sin[4t+pi/3] (Given)`
On comparing with`y=A sin(omegat+phi)`
`omega=4`
`T=(2pi)/omega=pi/2s`
When, `t=T/4`
`y=5 sin (pi/2+pi/3)`
`=5cos pi//3`
2,5m
`KE=1/2 momega^2[A^2-y^2]`
Substituting,A=5,m=2 then,
`KE=1/2xx2xx10^(-3)xx(4)^2[(5)^2-(2.5)^2]`
`therefore K.E=0.3j`