This applet simulates motion along a constrained path, such as a roller coaster would take (assuming it has safety wheels to keep it on the track in “up-side-down” situations, of course). The simulation offers a chance to explore a number of concepts associated with roller coaster physics, including conservation of energy, reaction forces and motion in a vertical plane.
The user can manipulate the track by means of control points. There are a number of example tracks accessed via the drop down menu on the bottom left. Control points can be added to the end of the track or removed from the end by the ΔN +1 or -1 buttons. The speed of the simulation can be modified by changing the calculation time step dt. A custom track can be saved or loaded by specifiying the filename and then using the save or load buttons.