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Momentum Calculator
Find total momentum for two objects moving along one line, or estimate their speeds after a collision. Set each direction with a positive or negative velocity and choose a coefficient of restitution from 0 to 1.
How do you calculate momentum and collision speeds?
Momentum is mass times velocity, p = mv, and the total is the signed sum for both objects. For a one-dimensional collision, this calculator uses the coefficient of restitution to estimate each final velocity. For example, equal 1 kg masses moving at +2 m/s and −1 m/s exchange speeds in an ideal elastic collision, while total momentum remains 1 kg·m/s.
Frequently asked questions
How do you calculate momentum and collision speeds?
Momentum is mass times velocity, p = mv, and the total is the signed sum for both objects. For a one-dimensional collision, this calculator uses the coefficient of restitution to estimate each final velocity. For example, equal 1 kg masses moving at +2 m/s and −1 m/s exchange speeds in an ideal elastic collision, while total momentum remains 1 kg·m/s.
Are my values uploaded?
No. The calculation runs in this browser; the values are not uploaded or saved.
What does a negative velocity mean?
It means the object moves in the opposite direction from the positive direction you chose. Keep the sign when entering both velocities; it affects total momentum and the collision result.
What does the coefficient of restitution mean?
It describes the relative separating speed after a one-dimensional impact compared with the approaching speed. Zero models a perfectly inelastic collision; one models an ideal elastic collision. Real materials can vary with impact conditions.
Is momentum conserved in every collision?
Total momentum is conserved in this model when the two-object system has no net external impulse. The calculator shows values before and after so you can compare them.
Does this calculator cover angled or rotating collisions?
No. It models motion on one straight line only. It does not calculate angles, rotation, object shape, sound, heat details or deformation.