What is Momentum in Physics?

Momentum in Physics:

The dynamical property arising from the combined effect of mass and velocity of a moving body is called its momentum.

Newton described momentum as a quantity of motion. The momentum of a body is the product of its mass and velocity. So, if m is the mass and v is the velocity of a body, then its momentum = mv. Thus a body’s momentum depends on both its mass and velocity. Mass is a scalar while velocity is a vector quantity. So, momentum is also a vector quantity. It has both magnitude and direction. The direction of momentum is the same as the direction of velocity.

Concept of Momentum:

Suppose, two identical trucks, one loaded and the other empty, are moving with the same velocity. In this case, the momentum of the loaded truck is greater than that of the other because of its greater mass. To stop within an equal interval of time, the loaded truck requires more force than the empty one.

Alternatively, let us consider two trucks of the same mass and the first one is moving with a higher velocity. So, its momentum is also higher. Here, again the same principle will apply. To stop the two trucks within the same interval of time, a greater force has to be applied against the first one.

Thus, the motion of a body isn’t described by its velocity only. It is described by the combination of mass and velocity i.e, the momentum of the body.