# Action Team

## Momentum: ( Mass X Velocity )

- The quantity of motion of an moving object measured as a product of its mass and velocity.

## Impulse: ( Force X Time)

- A motion produced by such a force

- The change in momentum depends on the force that acts and the length of time it acts.

How impulse affects momentum

- The impulse that an object experiences equals the change in momentum of an object.

## Why is an impulse greater when an object bounces than when the same object comes to a sudden stop?.

The impulse that is required to stop an object and then to throw or bounce it back up again requires time and it is greater than the impulse required to simply bring the object to a stop.

## The law of conservation of Momentum

-states that, in the absence of an external force, the momentum of a system remains unchanged.

## Elastic and Inelastic Collision

Elastic collision: Is a collision where the colliding objects bounce back without undergoing any deformation or heat generation.

Inelastic collision: Where the colliding objects are distorted and heat is generated.

## Impulse-Momentum relationship

Impulse shows that changes in momentum depend upon forces and time during which that force occurs.

Ft=Dmv

force times the time equals the mass times the change in velocity

Impulse= Change in momentum

Time is impulse and since the quantity M times V is momentum, the quantity M times ΔV must be change in momentum.

## In terms of impulse and momentum, why do air bags in cars reduce the chances of injury in accidents?

Because the person has to lose a certain amount of momentum, an equivalent amount of impulse must act on them, regardless of how quickly or slowly they stop. If less force acts, less damage will occur to the person. The airbag increases the time over which the person will be stopped in comparison to them hitting the windshield, steering wheel or the dashboard.

Woooo