Why does ice have no friction?

[scilearner]

If you come in contact with any object, it is not going to resist your movement right, why doesn't ice do this much. What chemical property is responsible for this?When I slide in ice, am I coming into less contact with ice, I don't understand. Thanks

[insane_alien]

ice has more than zero friction.

 

what happens with ice is that there is a thin layer of water on top of it. water works pretty well as a lubricant hence low friction.

[scilearner]

ice has more than zero friction.

 

what happens with ice is that there is a thin layer of water on top of it. water works pretty well as a lubricant hence low friction.

 

Thank you insane alien The water is smooth compared to the irregular texture of the floor, so there less friction.

[JamesNBarnes]

To add, you find ice "slippy" in general because there is water present, but that is not the whole story.

 

This only happens when there is pressure, the pressure your foot (for example) exerts on the ice, causes a very thin layer to melt, the resulting water acts as a lubricant. If it were cold enough (or the pressure was not significant enough) no water would be present and the ice would not be slippy.

 

You can demonstrate the principle to yourself like so:

 

Take two icecubes, straight from the freezer and gently sliding the cubes against each other and you will feel some friction. Now press them together quite hard and slide them, you will find that this causes the ice at the contact point to melt and the resulting water will lubricate the cubes, they will slip around quite easily.

 

If you apply direct pressure to the cubes (no sliding) then release the pressure, the cubes will actually stick together, as the water refreezes.

 

 

Also, think about ice skates, the contact area is quite small (compared to a whole foot) resulting in more pressure. There are more reasons they are shaped like that, for control etc, but the area (and therefore pressure exerted) is still important.

Hope that was helpful

[swansont]

To add, you find ice "slippy" in general because there is water present, but that is not the whole story.

 

This only happens when there is pressure, the pressure your foot (for example) exerts on the ice, causes a very thin layer to melt, the resulting water acts as a lubricant. If it were cold enough (or the pressure was not significant enough) no water would be present and the ice would not be slippy.

 

You can demonstrate the principle to yourself like so:

 

Take two icecubes, straight from the freezer and gently sliding the cubes against each other and you will feel some friction. Now press them together quite hard and slide them, you will find that this causes the ice at the contact point to melt and the resulting water will lubricate the cubes, they will slip around quite easily.

 

If you apply direct pressure to the cubes (no sliding) then release the pressure, the cubes will actually stick together, as the water refreezes.

 

 

Also, think about ice skates, the contact area is quite small (compared to a whole foot) resulting in more pressure. There are more reasons they are shaped like that, for control etc, but the area (and therefore pressure exerted) is still important.

Hope that was helpful

 

This was the conventional wisdom for some time, but it turns out that there is water present under conditions where pressure does not melt the ice, because the ice is too cold. This happens to be the case for the preferred temperature ranges for either figure skating or hockey; I can't recall which. But there is still water present under those conditions, so the ice is still slippery.

[JamesNBarnes]

I stand corrected, and found this article which loosely outlines several interesting things about ice.

 

http://www.nytimes.com/2006/02/21/science/21ice.html?pagewanted=1&_r=1