**Ch. 8: Momentum**

**Ch. 8: Momentum**

__Reading__

*College Physics*, Ch. 8

AP Classroom: Unit 5 "Momentum"

AP Princeton Review: Ch. 8

__Topics__

- Momentum is "mass in motion"
- We will study problems involving momentum and various kinds of collisions

__Labs__

- Roller Coaster Design Problem class presentations
- Collision weblab

__Linear momentum__

Momentum is "mass x velocity" (p = mv).

Thus, it can be thought of as "mass in motion".

We use the letter "p" for momentum, because the Latin word 'petere' means "to go to", "to attack". It's where we get the words "impetuous, petulant, and impetus"

__Collisions__

Many homework problems from this chapter are dealing with "collisions".

Rule #1: Total momentum is conserved in all types of collisions. "Conserved" means it "doesn't change".

Rule #2: In an "elastic" collision (perfect billiard balls), both Kinetic Energy

__and__momentum are conserved.

Rule #3: In an "inelastic" collision (billiard balls covered with Velcro), only momentum is conserved. Kinetic Energy is not.

__Impulse__

Impulse = Change in Momentum = Force x Elapsed Time = Mass x Change in Velocity

Impulse is a concept Newton came up with to develop his 2nd Law of Motion. We normally write the 2nd Law as "F=ma", but Newton originally expressed it using impulse.

__Collision weblab__

8._collision_weblab_handout_2024.docx |

__Homework__

Your homework is hosted in Canvas, along with the due dates.