A cone-shaped object placed on a slight incline oscillates back and forth as a stringless pendulum. Experimental and theoretical results are presented for two steel balls of different diameter joined together.

If a cone is set in motion on a horizontal surface, it rotates in a circular path. If the cone is placed on a steep incline, it will slide down the incline. If the cone is placed on a slight incline and released from rest, then it can oscillate from side to side as a stringless pendulum without sliding down the incline. The physics is not difficult to understand and could be examined by students as an example of an unusual type of pendulum. Experimental results are presented below using two steel balls of different diameter joined together, rather than a solid cone. Results with other conical objects are shown as supplementary videos.1 

Rolling motion of a truncated...

Supplementary Material

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