Marble Roller Coaster
Loops, hills and drops show kinetic and potential energy trading back and forth as a marble races the track.
Start building ↓The build
Lay the track
Split the foam tube lengthwise to make a channel.
Build a hill
Start high and shape a drop into a valley.
Add a loop
Form a vertical loop the marble can keep speed through.
Test runs
Release from the top and watch it complete the course.
At the top the marble has gravitational potential energy; as it drops, that converts to kinetic energy that carries it through loops and hills.
A closer look
Total mechanical energy is conserved minus friction, so each hill must be lower than the one before for the marble to make it.
Variables to test
- 1 Raise the start height — how big a loop can it clear?
- 2 Add a longer flat run; measure how friction slows it.
More Physics
Homopolar Motor
A single AA battery, a magnet and a copper-wire loop spin into the simplest electric motor that actually works.
Switchable Electromagnet
Coil insulated wire around an iron bolt and a battery turns it into a magnet you can switch on, off, and strengthen at will.
Pendulum Timer
A swinging mass keeps remarkably steady time — build one and discover what really sets its rhythm.