Games

Physics Experiments

Three classic experiments, each worked from the physics and held to it by tests. The beads slide without friction, and the tests hold the straight wire to its closed-form time, the cycloid to pi times the square root of R over g from any starting point on it, and forty bent cycloids to being slower. The slinky is an ideal one, a spring with no length of its own, as 120 masses joined by springs that only pull: its bottom first moves within 1% of the theory's square root of M over 3k, and its centre of mass falls freely to a tenth of a percent. Ours: the sizes and masses, and the drawing.

What's new

2026-10-07: Physics Experiments opens: the fastest slide (and a wire you draw yourself), beads on a cycloid bowl that all reach the bottom together, and a falling slinky in slow motion.

Try next

Physics in 3D Spin a top fast and it stands, slow and it falls. Roll a marble on a spinning record and it circles back to where it started. Watch a spring trade its bounce for a twist, and a T-handle flip itself over in space.
Physics Tricks Shake a pendulum fast enough and it balances upside down. Lift two balls of a Newton's cradle and two fly out. Throw a superball under a table and it comes back to your hand.
Desk Physics Stack sticky-note pads so the top one hangs wholly past the desk. Race a battery against a roll of tape. Pull paper from under a mug. Hear why a spinning coin whirrs faster as it settles. Every slider is something you can measure, so your phone's slow motion can check it.