This is another of Richard Walding’s suggestions for a Physics EEI. I tried it out, but encountered a lot of problems. There does appear to be an interesting relationship, though many more trials would be necessary to accurately determine it. I wonder if the relationship would be different for triangle or square-based prisms, compared to a cylinder?
Note: the weights I had only went up to 2.3 kg, so cylinders were not tested above this weight.