When coins are dropped from launching ramps, they begin spinning tangent to the curved surface, traveling in a circular motion. As the coins spin into the well, their rotational velocity greatly increases. Use the Vortx as a bank for your loose change or teach a Super! Wow! Neat!® science lesson. Great for teaching gyroscopic motion, rotational energy, law of conservation of energy, etc. 38 cm (15") high, 24 cm (9.5") diameter.