Plan the investigation
What students will do
Start with a guided comparison, then plan an investigation, analyze a graph, and check a prediction.
- Compare launch and flight. Use several spring compressions and compare horizontal velocity at the table edge with horizontal velocity during flight.
- Design and collect. Choose at least five projectile masses while keeping stiffness and spring compression fixed. Measure launch velocity consistently.
- Analyze a linear graph. Transform launch-speed and mass data. Use the best-fit slope to determine spring stiffness.
- Explain and predict. Connect spring energy with launch kinetic energy, then predict and test speed for an unused mass.
What students will learn
- Connect spring potential energy with launch speed.
- Distinguish horizontal launch motion from vertical falling motion.
- Linearize an energy relationship and infer spring stiffness.
Common misconception
Does doubling mass halve launch speed?
The energy model relates mass to speed squared; students test the resulting speed dependence.