Momentum

Linear momentum, translational momentum or simply momentum is the product of a body's mass and its velocity:

${\displaystyle \mathbf {p} =m\mathbf {v} }$

where p is the momentum, m is the mass and v is the velocity.

Momentum can be thought of as the "power" when a body is moving, meaning how much force it can have on another body. For example,

1. a bowling ball (large mass) moving very slowly (low velocity) can have the same momentum as a baseball (small mass) that is thrown fast (high velocity).
2. A bullet is another example where the momentum is very-very high, due to the extraordinary velocity.
3. Another example where very low-velocities cause greater momentum is the push of Indian subcontinent towards the rest of Asia, causing serious damages, such as earthquakes in the area of the Himalayas. In this example, the subcontinent is moving as slowly as few inches per year but the mass of the Indian-subcontinent is very high.

Momentum is a vector quantity, which has both direction and magnitude. Its unit is kg m/s (kilogram metre per second) or N s (newton second).

Momentum is a conserved quantity, meaning that the total initial momentum of a system must be equal to the total final momentum of the system. The total momentum remains unchanged.