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I was willing to understand a little bit better the physics behind iceskating.

Messy thoughts

From New Scientist (1964) (probably not the most up-to-date reference $\ddot \smile$), I found a diagram showing the relationship between both the static and kinetic coefficients of friction and the temperature (x-axis is reversed) for ice.

enter image description here

When we ice skate, we put a big pressure on the ice. As the ice is less dense than liquid water, this pressure may eventually be high enough to turn ice into liquid water. Intuitively I would think that high pressure would yield to high temperature but I suppose that this would hold true exclusively for gazes ($PV=nRT$). In any case, I don't quite have a good intuition for why warmer (or more pressurized eventually) ice would decrease the coefficient of friction of ice.

Questions

  • What is the intuition behind the fact the coefficient of friction of ice decreases as temperature increases?

  • Does the coefficient of friction of ice decreases with higher pressure too? For the same reason as above? As a correlated-side effect of increasing temperature?

  • Why do ice skates slide so well? Because it puts a high pressure on the contact surface or because it puts a high pressure on the contact surface which in turn increases the temperature?

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    $\begingroup$ Possible duplicate of What makes ice slippery? $\endgroup$ – ShankRam Feb 21 '16 at 8:51
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    $\begingroup$ I don't think this is a duplicate. The linked question is related but this one is specifically about the effects of temperature and pressure, which the linked question does not address. $\endgroup$ – bon Feb 21 '16 at 9:56
  • $\begingroup$ Maybe it has something to do with the effect of pressure on the melting point of ice. Check the phase diagram. As the pressure increases, the melting temperature decreases. I just don't know if the pressures under the blade of a skate are high enough to allow the ice to melt so that a layer of water could provide lubriction. You might check this using an estimate of the contact area and the weight of the person. $\endgroup$ – Chet Miller Feb 21 '16 at 12:47
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My understanding of ice skating is that it has to do with the pressure of the skate, melting the ice and you skate on the melted water. Look at the phase diagram of the water. At 1 atm, the water is solid, but at higher pressures (keeping the temp. the same) the water changes to a liquid.

enter image description here

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  • $\begingroup$ The effect is called regelation. You can cut ice with a thin steel wire and weights. Since ice expands when it freezes, pressure at the freezing point can cause thawing. $\endgroup$ – MarsJarsGuitars-n-Chars May 12 '18 at 20:06

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