Chapter 8.5, Problem 6SB

In Problems 5-8, an object attached to a coiled spring is pulled down a distance a from its rest position and then released. Assuming that the motion is simple harmonic with period $T$, write an equation that relates the displacement $d$ of the object from its rest position after $t$ seconds. Also assume that the positive direction of the motion is up.

$a=\text{10};T=\text{3}$ seconds