# How does iceskating work?

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.

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?

• Possible duplicate of What makes ice slippery? – ShankRam Feb 21 '16 at 8:51
• 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. – bon Feb 21 '16 at 9:56
• 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. – Chet Miller Feb 21 '16 at 12:47