KidzLabs Zero Gravity Fridge Rover. Wind up the rover gears and let it move up the fridge. Observe how it moves up the fridge surface, defying the force of gravity.
The Fridge Rover combines a magnet and a wind-up vehicle. Inside the clockwork mechanism, there is a coiled spring that winds up tightly as you turn the crank. This stores energy in the spring and, when you let go, the spring uncoils, releasing the stored energy and turning the wheels. The wheels can grip the surface of the fridge without failing because the magnet holds the Fridge Rover firmly against the fridge.
Age 8+