Elastic collision

How it is used

Contrasted with inelastic collisions, where some kinetic energy turns into heat, sound or deformation, and perfectly inelastic collisions, where the objects stick together. Collisions between gas molecules, or between billiard balls, are close to elastic.

Example sentences

1. Compare the total kinetic energy before and after to see whether it was an elastic collision.

2. In a head-on elastic collision between equal masses, the moving ball stops and the stationary one moves off with the same velocity.

Common collocations

• perfectly elastic collision
• inelastic collision
• head-on collision
• collide elastically

Related terms

• conservation of momentumThe principle that the total momentum of a system stays constant if no external force acts on it. The momentum before a collision or explosion equals the momentum after it.
• kinetic energyThe energy an object has because it is moving. It depends on mass and speed and equals one half times mass times speed squared (½mv²).
• momentumThe product of an object's mass and its velocity (p = mv). It is a vector and is measured in kilogram metres per second (kg·m/s).
• impulseThe effect of a force acting over a time interval, equal to force multiplied by time. It equals the change in an object's momentum and is measured in newton seconds (N·s).

More terms: Energy, Work and Momentum

• energy
• work
• power
• potential energy
• conservation of energy
• efficiency