# Magnetic Team

## Momentum

The quantity of motion of a moving body, measured as a product of its mass and velocity

## Impulse

A sudden strong and unreflective urge or desire to act; the change of momentum

The reason an impulse is greater when an object bounces than when the same object comes to a sudden stop is because the impulse required to bring an object to a stop and then throw it back again is greater than the impulse required to just bring it to a stop.

## Law of Conservation of Momentum

The principle that the total linear momentum of a closed system remains constant, unless an EXTERNAL force is applied

## Elastic Collision vs. Inelastic Collision

An elastic collision is one where there is no loss of kinetic energy and an inelastic collision is one where the kinetic energy is changed.

## Impulse-Momentum Relationship

Ft=Dmv

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

since we know force • time is impulse and since the quantity m•v is momentum, the quantity m•Δv must be change in momentum so the equation really says....

Impulse = Change in momentum

## Your friend says that the law of momentum conservation is violated when a ball rolls down a hill and gains momentum. What do you say?

The Law of Momentum Conservation states that if no external forces act on a system, then the system’s momentum will not change. If you treat the ball as your system, it is clear that the gravitational force is acting on the ball, provides an impulse, and therefore changes the ball’s momentum. But this is not a violation.

## Egg Drop

Egg Drop
From the height of 228 cm, the egg wrapped in bubble wrap took about .69 seconds to reach the ground.

## Ball rolling down a hill

The momentum of a ball rolling down a hill does not change unless an EXTERNAL force acts upon it. Although video #1 has gravity acting on the ball (eventually causing the momentum to change), video #2 has a greater external force acting upon it; the wall.

#1
#2