From: N. Gronert (ngronert@dcn.davis.ca.us)
Date: Mon Nov 27 2000 - 19:11:36 PST
Message-Id: <p04320402b648d0dbc547@[168.150.192.25]> Date: Mon, 27 Nov 2000 19:11:36 -0800 From: "N. Gronert" <ngronert@dcn.davis.ca.us> Subject: Frictionless ice
For the physical experience of it. . . I grew up in Minnesota and
"lived" at the outside ice rink. My brother and I and the others
bundled up warm enough to be out there, skated regularly at 0 F and
often enough at temperatures down to -25 F (below that I couldn't
keep my feet keep warm enough).
So, 1) it certainly didn't seem to me that at -25 F, that
there was any liquid on the ice, but the edges of the skates caught
enough grip to propel without making big furrows.
And, 2) at -15 C the ice was not more difficult to skate on.
Maybe much colder than that and it would be, but at around 0 F the
ice was just fine.
Nancy
ngronert@dcn.davis.ca.us
>Also, when someone sets an edge to push off
>from a skate, the pressure becomes enormous, but the blade digs a furrow in
>the ice and does not slip, although it must be very slippery in the blade
>direction. Since a furrow is dug, this seems to imply that that pressure
>is sufficient to liquify the ice?
> I do believe that
> >there must be a certain temperature below which ice skating is not easy,
>>though, I too do not have direct experience. I would imagine that it would
>>be lower than the -15 C I calculated due to some kind of localized heating
>>effects. It would be interesting to see, though, if folks have experienced
> >otherwise.
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