# The graph below shows the vertical displacement of a mass suspended on a spring from its rest position. Determine the period and amplitude of the displacement of the mass as shown in the graph. ?

As the graph reveals that it has a maximum value o displacement $y = 20 c m$ at t=0 , it follows the cosine curve with amplitude 20cm. It has got just next maximum at $t = 1.6 s$. So the time period is $T = 1.6 s$
$y = 20 \cos \left(\frac{2 \pi t}{1.6}\right) c m$