Collision Simulator
Classroom worksheet · Interactive simulation: https://lkforge.com/tools/physics/collision-simulator/
Name: Date:
Learning objectives
- Apply conservation of momentum to collisions.
- Distinguish elastic from inelastic collisions by kinetic energy.
- Predict outcomes for equal and unequal masses.
Variables to change
- Mass of each object
- Initial velocities
- Elasticity (elastic/inelastic)
Procedure
- Set two equal masses moving toward each other at equal speeds in an elastic collision.
- Make one object much heavier and repeat.
- Switch to a perfectly inelastic collision (objects stick) and compare.
Observations
Record velocities before and after, and note total momentum and total kinetic energy each time.
Questions
- Is momentum conserved in every collision here?
- Is kinetic energy conserved in an inelastic collision?
- Two equal masses collide elastically head-on at equal speeds. What happens?
- In a perfectly inelastic collision, what is true of the objects afterward?
- Write the conservation-of-momentum equation for a two-body collision.
Answer key (instructors)
- 1. Yes — total momentum is conserved in all collisions when no external force acts, elastic or inelastic.
- 2. No. Kinetic energy is conserved only in elastic collisions; inelastic collisions convert some to heat/deformation.
- 3. They exchange velocities and rebound with equal and opposite speeds.
- 4. They move together with a common velocity found from total momentum ÷ total mass.
- 5. m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂.
Momentum is conserved in every isolated collision. Elastic collisions also conserve kinetic energy (objects bounce), while inelastic ones lose kinetic energy to heat and deformation — perfectly inelastic objects stick and move together.