This applet animates the collision of two particles.
It also works out the final velocities, total momentum and kinetic energies.
Please try out by giving any masses and initial velocities.

If the applet does not appear, please try the following:
(1) Download the Java software from
(2) Go to the menu: Tools > Turn off Pop-Up Blocker.
(3) Tools > Internet Options > Advanced > Security > Allow Active Contents.
(4) Start Menu > All Programs > Java > Configure Java > Security and then add this website to the Exception Site List.

In an elastic collision, both momentum and kinetic energy are conserved.
In an inelastic collision, momentum is conserved but kinetic energy is reduced.
In a completely inelastic collision, the 2 particles stick together after collision.

Right-click here to download this page and the Java Class File.