Usian Bolt has reconfirmed his status as the fastest human on Earth, but is he faster than a person falling vertically with just gravity to propel them? Let's find out!
To answer this question, the folks at Minute Physics (video embedded below) checked the time from one of Bolt's 100-meter sprints, pitting it against the time it takes an Olympic platform diver to reach the water. Because diver's don't start from 100 meters up, they compared the first 10 meters of Bolt's run against the timing for a 10-meter platform dive.
If you were to simply drop a rock from the platform, it would actually hit the water before Bolt had covered the first 10 meters, but because divers tend to spring up slightly before plunging downward towards the water, it turns out that Bolt is actually quicker than a human opponent.
Both are still accelerating at the 10-meter mark, but if you could find a diver crazy enough to dive from 100 meters up (more than the length of a football field), he would be going almost 100 mph when he hit the water. Even Bolt tops out at around 28 mph during his sprint.
So I guess the answer to the original question is, it depends. Of course, raw gravity has to have the advantage: it's constant, tireless and accelerates the objects it affects over time.