[math-fun] Steps, paces & lightning bolts

FWIW: 6'5" Bolt took exactly 41 steps (20.5 paces; 1st & last step on his right foot) to win his new 100m world record (9.58s.); he supposedly topped 30mph at some point in the race. 2nd place took exactly 45 steps (22.5paces); the women's 100m winner took 50 steps (25 paces).