Momentum change and force.

Momentum:




Newtons first law:  A body will continue in a state of rest or in uniform motion unless an external force acts on it .
So it is evident from this law that we have to appply external forces to make the body move,and also we have to provide external forces to bring a body to rest or to increase the speed of the body.
Newtons second law: The rate of change of momentum is directly proportional to the force applied.
   
The equation derived from this important law  is :   force=   change in momentum
                                                                                                       change in time

As we also know the equation for momentum which is
   
  momentum = mass X velocity