1-D Collisions
Send two blocks toward each other on a frictionless track — adjust their masses, starting speeds, and coefficient of restitution to see momentum conservation and kinetic-energy loss in action.
Preview — sign up free to change the numbers yourself
What you can adjust
- Mass 1
- 0.5 – 10 kg
- Mass 2
- 0.5 – 10 kg
- Initial velocity 1
- -10 – 10 m/s
- Initial velocity 2
- -10 – 10 m/s
- Coefficient of restitution (e)
- 0 – 1
- Wall bounciness (wall e)
- 0 – 1
- First collision point
- -5 – 5 m
Mass of the left-hand block.
Mass of the right-hand block.
Block 1's starting velocity. Positive = moving right, toward block 2.
Block 2's starting velocity. Negative = moving left, toward block 1.
0 = blocks stick together (perfectly inelastic), 1 = no kinetic energy lost (perfectly elastic).
How elastic the side walls are. 1 = perfectly elastic (no energy lost bouncing off a wall). Below 1, the walls absorb energy so the blocks eventually come to rest.
Where along the track the two blocks first meet (0 = track midpoint). Only takes effect when the blocks are set up to approach each other; otherwise it's just a marker.
About this simulation
What it shows
Two blocks on a frictionless track, with a wall at each end, collide with each other and the walls. The results list the final speeds, the number of collisions and wall bounces, and the kinetic energy before and after.
The key idea
Total momentum is the same before and after each block-to-block collision. The coefficient of restitution decides how much kinetic energy survives: 1 keeps all of it, 0 makes the blocks stick together.
Try this
Set Coefficient of restitution (e) to 0 and run it: right after they meet the blocks move together at one shared velocity. At 1 they bounce apart with no energy lost.