Impulse

Definition

Impulse is the product of the average force applied to an object and the time duration over which it is applied. It is also equal to the change in momentum of the object.

5 Must Know Facts For Your Next Test

1. Impulse is a vector quantity, having both magnitude and direction.
2. The SI unit for impulse is Newton-second (N·s).
3. Mathematically, impulse $J$ can be expressed as $J = F \Delta t$, where $F$ is the average force and $\Delta t$ is the time interval.
4. Impulse can also be calculated using the change in momentum formula: $J = \Delta p$, where $\Delta p$ is the change in momentum.
5. In an isolated system with no external forces, total impulse on interacting bodies during a collision remains constant.

Review Questions

• How do you calculate impulse if given the average force and time duration?
• What is the relationship between impulse and momentum?
• What are the units used to measure impulse?

Related terms

Momentum:

A measure of motion of an object, defined as the product of its mass and velocity; represented by $p = mv$.

Force:

An interaction that changes the motion of an object when unopposed; measured in Newtons (N).

Collision: An event where two or more bodies exert forces on each other for a relatively short time.