Question

A body starts from rest its displacement is proportional to time square at constant?

Answer 1

From the derived equations of kinematic motion of objects, we derived the equations keeping the acceleration of the object constant.

So, by the second equation of motion,
s= ut+1/2*at^2
So, if u = 0 (initial velocity as it starts from rest)
S = 1/2*a*t^2

So, clearly displacement is proportional to t^2 at constant a i.e constant acceleration.