A $2\mathrm{.}00$ kg$,$ frictionless block is attached to an ideal spring

with force constant $300$ N$/$m$.$ At t $=0$ the spring is neither stretched

nor compressed and the block is moving in the negative direction at $12\mathrm{.}0$ m$/$s$.$ Find $($a$)$ the amplitude and $($b$)$ the phase angle. $($c$)$ Write an equation for the position as a function of time.

but assume that at t $=$ O the block has velocity $-4\mathrm{.}00$ m$/$s and displacement $+0\mathrm{.}200$ m away from equilibrium.