Write the equation of `SHM` for the sitution shown below :

Explanation

General equation of `SHM` can be written as `x = Asin(omegat+phi)`
At `t = 0, x = A//2 rArr (A)/(2) = Asinphi rArr phi = 30^(@), 150^(@)`
Also at `t = 0, v = -ve, Aomega cosphi = -ve rArr phi = 150^(@)`