Description
What makes an interaction a collision and what makes it an explosion? In this AP Physics C: Mechanics video, we define the collision model (brief, strong forces between objects, much larger than the net external force) and the explosion model (internal forces push objects apart), and we see why kinetic energy stays the same or decreases in a collision but increases in an explosion. We classify real interactions, draw before-and-after diagrams, and review all of 4.1 before moving on to impulse in 4.2.
In this video:
0:00 Hook: bat and ball, spring launcher, fireworks
1:05 The collision model
2:00 The explosion model
3:10 Example: classify the interaction
4:10 Example: before-and-after diagram
5:09 The big picture: reviewing 4.1
6:04 Preview of 4.2: force and impulse
Download the guided notes and practice problems for this unit at houstonscience.com.
Part of the AP Physics C: Mechanics Unit 4 (Linear Momentum) series.