Coaster Creator Drag the black nodes to shape a track, then launch. The train is released from rest at the first node — that height is all the energy it will ever get.

How to use this simulation

1. Design the track. Drag any black node to shape hills and valleys. Nodes keep their left-to-right order, so the track can never cross itself.
2. Predict first. Before launching, think about where potential, kinetic and thermal energy will be greatest. The box at the first node shows the starting energy, PE = mgh.
3. Launch and watch the bar. Red is potential energy, green is kinetic, orange is thermal energy lost to friction and air. The bar's total width never changes — energy is only converted, never created or destroyed.
4. Iterate. If the train stalls or crashes, change the track and run it again. Notice what changed and why it helped.
5. Keyboard controls: click the picture, then Tab / Shift+Tab to step between nodes, ←↑↓→ to move the selected node (hold Shift for bigger steps), Space to launch.

The model: the train starts at rest, so its total energy is mgh at the first node. Rolling friction (μ × the normal force, which grows in valleys) and air drag steadily convert that into thermal energy. Because friction scales with mass but air drag does not, a heavier train coasts slightly farther — compare 1 car with 6. Real coasters keep the force on riders under about 5 g; above 6 g this simulation calls it a crash.