Tuesday, April 28, 2009 - Block 2

Collect RA 5.2

Show parts of video dealing with railroad cars.

Momentum Quiz

Intro to conservation of momentum: If no net external force acts on the system, then there is no change in momentum.

Conservation of Momentum has never been shown to fail. It does not apply in cases in which there is an external force, such as dropping an object.

Applied Conservation of Momentum to collisions.
Two basic types of collisions:
1. Elastic (Things bounce)
2. Inelastic (Things stick)
If there is no net external force, momentum is conserved in both types of collisions.

Demos with air track for both types of collisions.

Worked inelastic collision problems on board showing problems solving strategy.

Students worked on and handed in Elastic Collision Worksheet.

Homework: RA 5.3, CD chapt 5