Momentum

Didn’t he pay attention when the teacher was talking about momentum? Now I will never get those chips!

Explain what is happening in the picture…

• Why did the blond-haired kid miss getting the chips?

• What does the kid need to do in order to get the chips?

Momentum

• Depends on an object’s mass and the object’s velocity.

• The amount of momentum NEVER changes…it is just transferred to another object.

• p = m x v (p = momentum)

Examples of objects with momentum

• A car driving down the road

• A person running

• A wrecking ball

• A frisbee in the air

• A football player tackling another player

Solving for Momentum

p = m x v

Units are kg • m/s

kg is from MASS (m)

m/s is from VELOCITY (v)

Example

• What is the momentum of a 6 kg bowling ball that is moving at 10 m/s down the alley toward the pins?

6 kg x 10 m/s = 60 kg • m/s

Another Example

• An 85 kg man is jogging with a velocity of 2.6 m/s North. Nearby, a 65 kg girl is skateboarding and is traveling with a velocity of 3 m/s South. When they collide, who is hit with more momentum?

Answer

• Man’s momentum = 85 kg x 2.6 m/s

221 kg • m/s

Girl’s momentum = 65 kg x 3 m/s

195 kg • m/s

The girl is hit with more momentum! OUCH!!!

Law of Conservation of Momentum

• Any time objects collide, the total amount of momentum stays the same. Momentum cannot be lost…only transferred!!

Examples

• Pool balls colliding on a pool table

• Bumper cars

• Boxing

• A dog running into a wall