Description
Why does an airbag reduce injuries when the change in momentum is the same? In this AP Physics C: Mechanics video, we show that a longer collision time means a smaller average force for the same impulse, compare bouncing with sticking, and find the change in momentum for straight and angled bounces off a wall. Worked examples include a ball that sticks or bounces, a person landing stiff-legged or with bent knees, and an angled bounce.
In this video:
0:00 Hook: how does an airbag reduce injuries?
0:56 Collision time and average impact force
2:41 Bouncing versus sticking
4:31 Angled bounces
5:30 Example: stick or bounce
8:08 Example: landing stiff or bent
11:07 Example: angled bounce
13:38 Preview: impulse versus work
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.