Elastic and Inelastic

The next 2 systems demonstrate one of the fun features of Gravitation3D – collisions.  This system demonstrates elastic collisions (collisions that conserve kinetic energy).  These can be likened to billiard ball collisions.  The next system demonstrates inelastic collisions, which don’t conserve kinetic energy and can be likened to collisions of silly putty.  This first system is quite unstable, the sets of planets making only a few orbits before chaos sets in.

Special Features Demonstrated:

• Elastic collisions

• Changing the Field of View

• Star controls

This is the inelastic system.  After two planets collide, they stick together, becoming one larger planet with the combined properties of each (mass, volume, center of mass, color).  Though kinetic energy is not conserved when a collision occurs, momentum is conserved.  Note that no planets in this system were given any initial velocities.  So the net momentum of the starting system is 0.  After all the collisions, you can see that momentum was conserved since the final large planet does not move.  This final mega planet has the total mass and volume of the original system and lies at the center of mass of the original system.

Special Features Demonstrated:

• Inelastic collisions

• Reversing the background color

• Wireframe mode

• Ambient lighting control