BOOM!!

 

One of the most powerful laws in physics is the law of momentum conservation. The law of momentum conservation can be stated as follows.  For a collision occurring between the blue car and red car in the picture above, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision. That is, the momentum lost by the blue car is equal to the momentum gained by  red car.

For this collision, the forces acting between the two objects are equal in magnitude and opposite in direction. This statement can be expressed in equation form.  The forces act between the two objects for a given amount of time. In some cases, the time is long, in other cases the time is short. Regardless of how long the time is, it can be said that the time that the force acts upon object 1 is equal to the time that the force acts upon object 2.