Plan the investigation
What students will do
Use the student handout to organize predictions, measurements, and explanations.
- Predict the rebounds. Compare matched carts approaching soft and stiff spring bumpers. Predict peak force, contact duration, and final speed.
- Inspect force pulses. Measure contact start and end times and peak forces. Sketch both signed force–time pulses together.
- Compare impulse and momentum. Find signed force areas and calculate momentum changes using measured rebound velocities.
- Explain the tradeoff. Compare average and peak force to explain how a softer bumper changes the collision while producing a similar rebound.
What students will learn
- Determine impulse from signed force–time area.
- Calculate momentum change for a reversal of direction.
- Distinguish peak force, average force, and contact duration.
Common misconception
Does a larger peak force always mean a larger impulse?
Impulse depends on the full force–time area, including contact duration.