Momentum

Definition

Momentum is the product of an object's mass and its velocity. It is a vector quantity, meaning it has both magnitude and direction.

5 Must Know Facts For Your Next Test

1. The formula for linear momentum is $p = mv$, where $p$ is momentum, $m$ is mass, and $v$ is velocity.
2. Momentum is conserved in a closed system with no external forces, according to the law of conservation of momentum.
3. Impulse, defined as the change in momentum, is equal to the force applied times the time interval over which it acts: $J = F\Delta t$.
4. In collisions, elastic collisions conserve both momentum and kinetic energy, whereas inelastic collisions conserve only momentum.
5. Newton's Second Law can be expressed in terms of momentum: $F = \frac{dp}{dt}$, where $F$ is force and $\frac{dp}{dt}$ represents the rate of change of momentum.

Review Questions

• What is the formula for linear momentum?
• Explain how impulse relates to momentum.
• Describe how conservation of momentum applies in a collision.

Related terms

Impulse:

The change in an object's momentum resulting from a force applied over a time interval. It is given by $J = F\Delta t$.

Conservation of Momentum:

A principle stating that the total linear momentum of an isolated system remains constant if no external forces act on it.

Elastic Collision:

A type of collision where both kinetic energy and momentum are conserved.