Three Sided Coin

December 12, 2020

The three sided coin is a specially constructed circular coin described in[1] such that the probability of landing on the head, tail or side of the coin is approximately 1/3.

Among the possible applications is to help decide the outcome of a three way contest.

To use, toss the coin into the air by hand while imparting a spin about the transverse axis so the the coin rotates rapidly head-over-tail. Allow the coin to fall onto a soft surface such as grass or carpet. The head of the coin is marked by a small depression in the center.

The following graph shows the result of 100 tosses of the three sided coin onto a grassy surface.

(image)

Bibliography

  • [1]  Ee Hou Yong, L. Mahadevana, Probability, geometry, and dynamics in the toss of a thick coin. American Journal of Physics 79, 1195 (2011)