1. Exam correction deadline is today by 4:45.
Reminders
Exam correction deadline is today by 4:45.
Vocab deadline is tomorrow. (7th & 8th)
Extra credit is due November 25th.
If you got below an 80 on the lab yesterday, you may come in next week to re-do it.

2. Conservation of Momentum

3. Conservation of Momentum
Momentum must be conserved.
This fact means that the momentum in a specific direction before a collision must be equal to the momentum in that same direction after the collision.
Consider the two identical pucks to the right.
In the first collision, momentum is conserved because the first puck completely stops and the second puck departs with the same initial momentum as the first puck in the same direction as the first puck.
In the second collision, momentum is conserved because both pucks move off with one half the speed of the first puck before the collision and in the same direction as the first puck.
Why isn’t the momentum conserved in the collision to follow?
The second puck moved with the same speed but in a different dimension.
Therefore, momentum was not conserved in this collision.

4. Momentum – Elastic Collisions
Elastic Collision – a collision in which the colliding bodies do not stick together.
The equation used for elastic collisions is as follows.

5. Momentum – Inelastic Collisions
Inelastic Collision – a collision in which the colliding bodies stick together.
The equation used for elastic collisions is as follows.
Physics Rules, Inc.

6. Momentum
Identify the number and types of collisions in the animation below.

7. Momentum
Identify the number and types of collisions in the animation below.

8. Momentum
Identify the number and types of collisions in the animation below.
Laser

9. Momentum
Identify the number and types of collisions in the animation below.
The Bolt

10. Momentum – Elastic Collisions WS 27 -1
What type of collision is depicted in the collision of the offensive paddle and the hockey puck?
What about the collision with the defensive paddle?
If the offensive paddle (m = 0.5 kg) was traveling at 0.75 m/s before the collision and 0.25 m/s after the collision, then how fast was the puck ( m = 0.2 kg) moving after the collision?

11. Momentum – Elastic Recoil Collisions
Recoil can be understood by considering the result of the explosion of the gun powder on a gun.
The bullet flies in one direction while the gun recoils in the other direction.
Laser

12. Momentum – Inelastic Collisions WS 27 - 2
An explosive bowling ball (m1 = 10 kg, v1I = 10.0 m/s) rolls towards a gun as shown. The gunman hopes to keep the ball away by shooting a bullet (m2 = 1.1 kg, v2I = 95.0 m/s) into the ball.
What type of a collision is the one depicted here?
What is the final velocity of the bowling ball?
Laser