The rectilinear motion is given as:
s = s0 + v0 t + (1/2) a t^2
We can see that the variables stand for:
s = final distance
s0 = initial distance
v0 = initial velocity
t = time
a = acceleration
We can see that all these variable are always constant EXCEPT acceleration. The rectilinear motion can only be applied if and only if acceleration is CONSTANT.
