COLD HARD SCIENCE. The Physics of Skating on Ice

[jayrandom]

Попался интересный ролик с некоторыми подробностями езды и манёвров на льду:
"The Physics of Skating on Ice".

В частности, есть замедленная съёмка приземления пируэтов в фигурном катании, и замедленная съёмка хоккейного торможения. Познавательно.

Comments

[golger-i.livejournal.com]

Кстати, так до сих пор и непонятно, почему лед скользкий! Ведущий гдеъто там заикнулся про friction melt, уже хорошо, что миф про давление, вроде, умер.

[jayrandom.livejournal.com]

Википедия не знает:

Ice was originally thought to be slippery due to the pressure of an object coming into contact with the ice, melting a thin layer of the ice and allowing the object to glide across the surface.[citation needed] For example, the blade of an ice skate, upon exerting pressure on the ice, would melt a thin layer, providing lubrication between the ice and the blade. This explanation, called "pressure melting", originated in the 19th century. It however did not account for skating on ice temperatures lower than −4.0 °C, which skaters often skate upon.

In the 20th century an alternative explanation, called "friction heating," was proposed, whereby friction of the material was the cause of the ice layer melting. However, this theory also failed to explain skating at low temperature. Neither sufficiently explained why ice is slippery when standing still even at below-zero temperatures.[9]

It is now believed that ice is slippery because ice molecules in contact with air cannot properly bond with the molecules of the mass of ice beneath (and thus are free to move like molecules of liquid water). These molecules remain in a semi-liquid state, providing lubrication regardless of pressure against the ice exerted by any object. However, the significance of this hypothesis is disputed by experiments showing a high coefficient of friction for ice using atomic force microscopy.[10]

-- http://en.wikipedia.org/wiki/Ice