Investigating Momentum
Instructions
Investigating Momentum is a free interactive simulation of elastic and inelastic collisions for GCSE Physics (Edexcel IGCSE 4PH1). Students vary the mass and velocity of two trolleys and measure momentum before and after a collision to investigate whether momentum is conserved. No login required — includes a worksheet and self-marking quiz.
Aim: To investigate whether momentum is consrved in a collision.
Trolley 1
Trolley 2
Experiment Results
Before Collision
| # | Collision Type | m₁ (kg) | v₁ before (m/s) | m₂ (kg) | v₂ before (m/s) | p₁ before (kg m/s) | p₂ before (kg m/s) | p total before (kg·m/s) |
|---|---|---|---|---|---|---|---|---|
After Collision
| # | Collision Type | m₁ (kg) | v₁ after (m/s) | m₂ (kg) | v₂ after (m/s) | p₁ after (kg m/s) | p₂ after (kg m/s) | p total after (kg·m/s) | Notes |
|---|---|---|---|---|---|---|---|---|---|
Physics Explanation
Conservation of Momentum: In an isolated system, the total momentum before a collision equals the total momentum after the collision.
Momentum formula: p = m × v (mass × velocity)
Elastic Collision: Objects bounce off each other with no loss of kinetic energy.
Inelastic Collision: Some kinetic energy is converted to other forms (like heat or sound).
Perfectly Inelastic Collision: Objects stick together after collision, moving with a common velocity.
- Set the masses and initial velocities of the two trolleys using the sliders.
- Keep the collision type set to "Elastic" for now.
- Click "Start Simulation" and observe the collision.
- Click "Capture Results" to record the mass and velocity of each trolley before and after the collision.
- Calculate the momentum of each trolley (p = m × v) before and after the collision, enter your values into the table, then use "Check Answers" to confirm them.
- Repeat for a range of different starting scenarios — e.g. both trolleys moving towards each other, one trolley initially at rest, or both moving in the same direction.
- Is the total momentum the same before and after the collision in each case?
- Now repeat the whole investigation for "Inelastic" and "Perfectly Inelastic" collisions. Is momentum still conserved? What happens to the total kinetic energy in each case, and how does that differ from what happens to momentum?