Suppose an object starts moving at u and gains an acceleration of a. After time t, it gets a speed v after travelling a distance of s.
a = (v - u) / t => v - u = at
v = u + at
s = ut + 1/2(v - u) t
s = ut + 1/2 (at) t
s = ut + 1/2 at2
s = ut + 1/2 at2
v2 = (u + at)2
v2 =u2 + 2uat + a2t2
v2 = u2 + 2a (ut + 1/2 at2)
v2 = u2 + 2as
v2 = u2 + 2as