Build your own circuits from logic gates.
Displacement, velocity and acceleration
Create your own plots of displacement, velocity and acceleration.
Simulation of Keplerian orbits.
Simulation of image formation by lenses.
Browse the absorption lines in the Sun's spectrum.
Simulation of ions forming into crystal lattices, like NaCl.
Using a tank of bouncy balls to demonstrate statistical dynamics.
How line emission from hydrogen atoms arises.
Build your own electronic circuits.