Water-running conundrum

[doug_c]

You have a 100m long swimming pool, with 5 feet of water.
Michael Phelps races Usain Bolt, and wins by a long way.
Now you drain the pool till the water is only a foot deep. Sneakers are optional.
Usain wins by a long way.

Question, at what depth would the race be a dead heat?

[nschnabel]

There would be no dead heat.

If the water is deep enough to swim (?3 feet?- I'll defer to triathletes/swimmers), Phelps wins. If the water is not deep enough to swim, Bolt wins. I would pay to see the race in about 2 feet of water, though.

Nick

[Chachi]

Now, at some point, there has to be a dead heat. I believe this would involve both athletes running with an occasional swim and dive from Phelps (but Bolt can also do the same). It isn't stated that Phelps has to swim and Bolt has to run. Or, in how much water can Bolt run at the same pace as Phelps swim because Phelps can easily swim in 18" of water. Leg lifts would be tough but possible at this depth. Now taking careful consideration of Phelp's wing span, shoe size, favorite color and Bolt's inseam, shoe size and favorite number, it is quite obvious that 25.1" of water is where there would be a photo finish.

Chachi

[doug_c]

I think it's deeper than 25.1". Heck, I think even I might beat Phelps in 25.1". That's too shallow for him to swim optimally. Plus he doesn't get a dive or a flip turn. I think Usain can get some big air between strides, so I'm going with 32". Phelps can swim fairly close to max speed in that depth (a deep pool is faster, plus he will ideally want about 35" to avoid touching the bottom). Usain only has to go a little over walking speed to win.