Force

It is an important factor in the field of Engineering Science, which may be defined as an agent which produces or tends to produce, destroy or tends to destroy the motion. According to Newton's second law of motion, the applied force or impressed force is directly proportional to the rate of change of momentum. We know that,

Momentum = Mass x Velocity

Where, 

             m = Mass of the body

              u = Initial velocity of the body

              v = Final velocity of the body

              a = Constant acceleration

               t = Time required to change the velocity from u to v.

So, Change of momentum = mv-mu

and the rate of change of momentum, = (mv-mu)/t = m.(v-u)/t = m.a

So, We can write Force, 

F α m.a

F = k ma

Where, k is a constant of proportionality

For the sake of convenience, the unit of force adopted is such that it produces a unit acceleration to a body of unit mass.

F = ma

Force = Mass X Acceleration