Radius (m) 0.25 0.40 0.15 Time per 15 revolutions 6.71 s 7.83 s 5.04 s Period (s) 0.41 s 0.52 s 0.34 s Expected Value 0.502 s 0.594 s 0.388 s Percent Error 11.8% 12.5% 11.8%