# Car on road with "infinite" friction

## Main Question or Discussion Point

I have been wondering this for a while. I know that tires using static friction due to reasons that I forget and therefor maintain good traction with asphalt. A few years ago family member said that if there was too much friction on a road then a car wouldn't move, but I argued that the car would move better. What would happen to a car driving on a road of infinite mu? Would you move like normal but be able to stay on through any type of turn?

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First, infinite mu ( according to the microscopic analysis of friction) would mean that the car can't move at all ( in the sense that the road forms such strong bonds with the tyre that they never come apart).. Having said that, I think you're right that better friction would, in theory, enable the car to move better.. But there will be a certain limit to that. Too much friction causes the tyres to wear down quickly.

First, infinite mu ( according to the microscopic analysis of friction) would mean that the car can't move at all ( in the sense that the road forms such strong bonds with the tyre that they never come apart).. Having said that, I think you're right that better friction would, in theory, enable the car to move better.. But there will be a certain limit to that. Too much friction causes the tyres to wear down quickly.
Yeah that is why I put the infinite in quotes in the title, and that was what my train of thinking was that too much would slow it and but too little it cant hold.

A.T.
I have been wondering this for a while. I know that tires using static friction due to reasons that I forget and therefor maintain good traction with asphalt. A few years ago family member said that if there was too much friction on a road then a car wouldn't move, but I argued that the car would move better. What would happen to a car driving on a road of infinite mu? Would you move like normal but be able to stay on through any type of turn?
You must differentiate between static friction coefficient, and rolling resistance coefficient. Extremely high static friction coefficient will not prevent the wheel from rolling, just from slipping. Think of indestructible gears on a toothed rack.

Oaxaca, CWatters and Hornbein
You must differentiate between static friction coefficient, and rolling resistance coefficient. Extremely high static friction coefficient will not prevent the wheel from rolling, just from slipping. Think of indestructible gears on a toothed rack.

Infinite rolling resistance, I never thought of that. I guess you could be using bags packed loosely with sand as tires.

Years ago I remember doing a little experiment similar to your question. I happened across a steel ball coated in rubber. So I acquired a steel ball of almost identical size and rolled them both with equivalent force across a sheet of glass. The steel ball clearly rolled far easier and further. The additional friction created by the rubber not only gave better traction, but made the ball harder to move. So I suggest in practical terms infinite friction would enable infinite traction but render the car impossible to move.