- #1
Mayan Fung
- 131
- 14
As far as I know, ice skating works because high pressure lowers ice melting point. A thin layer of water forms between the blades and the ice which greatly reduces the friction.
Just now, I am reading a thermodynamic book. For the phase boundary between ice and water, dP/dT ~ 135bar/K. Assuming a man with weight 600N, blade area ~ 2.5mm x 20 cm x 2 ~ 10^-4 m^2. The pressure is around 60 bar. So it only changes the melting point by about 0.44°C.
The book claimed that this is not a significant change. The ice won't melt unless the temperature is already very close to 0°C.
If the book is right, what is the real mechanism for ice skating?
If the book is wrong, which means the mechanism is true, does it mean that if the ice is, say -1°C, we can't glide on the ice?
Just now, I am reading a thermodynamic book. For the phase boundary between ice and water, dP/dT ~ 135bar/K. Assuming a man with weight 600N, blade area ~ 2.5mm x 20 cm x 2 ~ 10^-4 m^2. The pressure is around 60 bar. So it only changes the melting point by about 0.44°C.
The book claimed that this is not a significant change. The ice won't melt unless the temperature is already very close to 0°C.
If the book is right, what is the real mechanism for ice skating?
If the book is wrong, which means the mechanism is true, does it mean that if the ice is, say -1°C, we can't glide on the ice?