# Question 4120e

Jan 14, 2017

#### Answer:

Velocity and acceleration describe the motion of a single object.

#### Explanation:

Momentum (p) is measured by the product of mass and velocity.

$p = m v$

The momentum is directly proportional to an object's velocity, so its vector is along the same direction as the velocity. $p$ is also proportional to the mass of an object.

That being said, momentum is a way to describe a motion of an object by looking at the product of its mass and velocity.

Jan 14, 2017

#### Answer:

Momentum shows the level of difficulty in decelerating an object. Or put another way, the "unstoppability" of an object.

#### Explanation:

Momentum shows the level of difficulty in decelerating an object. An object with large momentum requires a large force to act over a short time to bring it to rest, or it requires a smaller force to act over a larger period of time to bring it to rest.

The change in momentum is equal to the product of force applied and the time over which the force acts.
Δp=F × Δt#

Change in momentum is called impulse, so this answer is based on the definition of impulse but it does give some meaning to momentum as a quantity.