Recoil Concept

Demonstrations in Recoil

Black medicine ball sitting on a small metal rolling cart (physicist's skateboard) with casters, next to a wooden meter stick on the floor

Skateboard and Medicine Ball

Demonstrates Newton's Third Law and momentum conservation through recoil. Kneeling on a rolling cart, throw medicine balls horizontally — the cart rolls backward. Throwing two balls approximately doubles the distance; …
Person in blue sneakers and jeans standing on a large black wheeled platform with caster wheels on tile floor, red warning text reading 'Avoid Personal Injury DO NOT STAND' visible on the surface, metal handle at one end
Safety

Physicist's Skateboard

Stepping off a low-friction wheeled platform demonstrates Newton's Third Law: the board recoils backward as the demonstrator steps forward. Also illustrates conservation of momentum — the board's higher recoil speed …