Q5 Q19.) Choose the correct formula for the displacement d from the rest position of the object attached to the spring at time t. Show your details as to how you got your answer.
simple harmonic motion eqn: d = A*sin(wt + p) where d is displacement, A is amplitude, p is phase angle and w is angular velocity = 2pi/T where T is period
at t = 0, d = 0 so p = 0 at t = 0, it moves downward so d is negative A = -2 w = 2pi/4.5 = 4pi/9
