written by Fu-Kwun Hwang and Wolfgang Christian
edited by Robert Mohr

This interactive simulation allows students to explore two-dimensional elastic collision between hard disks in an isolated system. The user can modify the mass, position and velocity of each disk using sliders.  Both disks are draggable, allowing students to set up one-dimensional and two-dimensional collisions. A checkbox option will pause the simulation at the moment of collision, and then display arrows showing the momenta of each disk immediately before AND after the collision. Red arrows depict the change in momentum resulting from the collision. The instructions explain how to set up equations to calculate both the total energy and total momentum of the system after the collision.

See related materials for a link to a simpler Easy Java Simulation that models a one-dimensional collision.
See Annotations for an editor-recommended tutorial on momentum and its conservation.

This resource is distributed as a ready-to-run (compiled) Java archive.   In order to modify the simulation (and see how it is designed), users must install the Easy Java Simulations Modeling and Authoring Tool. SEE RELATED MATERIALS for a link to install the EJS modeling tool.

• Download ejs_mech_ElasticCollision.jar - 1184kb Java Archive File

Last Modified June 13, 2014

This file has previous versions.

The source code zip archive contains an XML representation of the Two Particle Collision Model.  Unzip this archive in your EJS workspace to compile and run this model using EJS.

• Download ejs_ntnu_mech_ElasticCollision.zip - 10kb Compressed File

Last Modified December 2, 2008