Question

How would you derive 1st equation of motion?

Answer 1

Consider a body initial moving with velocity "Vi". After certain interval of time "t", its velocity becomes "Vf". Now

Change in velocity = Vf - Vi

OR

DV =Vf – Vi

Due to change in velocity, an acceleration "a" is produced in the body. Acceleration is given by

a = DV/t

Putting the value of "DV"

a = (Vf – Vi)/t

at = Vf – Vi

at + Vi =Vf

OR

Vf = Vi + at