# How fast would someone have to run to run over water?

I was thinking about Flash, the superhero, or the little boy in the Incredibles.

There is one Yahoo answer that doesn't answer a lot. Especially, I don't think surface tension would help a lot for a human to run over water, I think one would have to build on the inertial effect of the water.

There is one empirical approach based on figuring out the speed at which bare-footed water skiing is done, but I wasn't able to find a decent number. Still the difference may be that a hypothetical runner would have to propulse herself over the water, which may or may not make the thing more difficult.

Hence, I raise the question here.

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I think it might not matter how fast you run, but how much you push down. – Alan Rominger Aug 20 '12 at 20:05
@AlanSE, I think one would have to assume that the downward component of force would be equal to (or slightly more than) the weight of the runner; I'm not sure how this could be varied. – AdamRedwine Aug 20 '12 at 20:43
Well, if you could run this fast... – Mike Dunlavey Aug 20 '12 at 21:02
@AdamRedwine if you are running with your feet hitting at an angle to the water then it will be a component of your forward speed. This is the limit to the speed of sprinters on a track, how hard they can push down, and so how much friction they can generate – Martin Beckett Aug 20 '12 at 23:14