Impulse
Formula: I = F ⋅ t
Impulse (I) is the product of the force (F) applied to an object and the time period (t) over which it is applied. It is a vector quantity, possessing both magnitude and direction. The impulse experienced by an object is equal to the change in its momentum. The longer the force is applied and/or the greater the force, the greater the impulse will be. Impulses are generally measured in Newton-seconds (Ns) or pound-seconds in the British imperial system.
In a practical sense, understanding impulse can help in analyzing collisions in sports or traffic accidents, modifying how airbags deploy to maximize their effectiveness, and in rocket science to determine how long an engine needs to fire to achieve a desired change in momentum.