A particle executes simple harmonic motion with an amplitude of 10 cm and time period 6 s. At t = 0 it is at position x =5 cm going towards positive x-direction. Write the equation for the displacement x at time t. Find the magnitude of the acceleration of the particle at t = 4 s.

Given,
Amplitude, A = 10cm
time period, T = 6 sec
we know,

equation of SHM,

at t = 0, x = 5
The expression will become,



hence, equation of SHM,

we know, acceleration,
at t = 4sec,





so, acceleration, 
