On Thu, 15 Jan 2009 22:33:05 GMT, Tom Francis - SWSports
wrote:

On Thu, 15 Jan 2009 16:48:20 -0500, "D.Duck" wrote:

Concerning the recent crash one of the TV commentators said that it was
better for the airplanes survivability that the water in the Hudson is cold
and not warm. the reason he said is that cold water is *harder* than warm
water and made for better ditching conditions.

Any truth to this.

No - cold water is less dense than warm water.

That's why ice floats.

What you say??? Nope. Ice floats because it goes through a phase
change and expands when it freezes.

Liquid water density decreases as temperature goes up EXCEPT for a
very strange behaviour in that it's maximum density is at 4 degrees C
and drops from there down to 0, where it freezes. So from 4 degrees C
on up, colder water is more dense than warmer water. But the
difference in density is so slight I doubt it would make any
difference to a plane crashing on it.

Steve