Motion of Polygonal Prisms Down Inclined Planes

An experiment was carried out to determine the rolling times of square, hexagonal and circular prisms down inclined ramps of various angles. Each roll was recorded on video and rolling times were determined by counting frames. A model was created to predict the times of descent for n-sided prisms under the assumption of persistent contact between prism and ramp. A second model was created without this assumption. Animations of the prisms’ motion were created according to the models. Predicted times of the models approached experimental times for polygonal prisms as the number of sides increased. Notable properties of the rolling motions are discussed, and reasons for discrepancies between models and results are addressed.