Can anyone tell 4th equation of motion.

Dear student, 

We know the first equation of motion,
v = u + at
Second equation of motion,
s = ut + 1/2 at²
The third equation of motion,
v² = u² + 2as
The fourth equation of motion,
The distance travelled by a body in t^th second (S_t) = The difference between the distance travelled in t seconds and distance travelled in (t-1) seconds.
S_t =( ut +1/2 at² ) - {u(t-1) + 1/2 at²}
    = u + a [n - 1/2]

where:
u = initial velocity, v = final velocity, a = uniform acceleration, s= distance travelled, t = time period in seconds


Regards.