How does change in temperature of an object affect its friction?

If it does affect, would this be measurable?


Also, why does it affect it?How does change in temperature of an object affect its friction?
The effect has been ';measured';, sometimes with fatal results, by those who drive cars extremely hard. When brake linings get very hot, the friction reduces and the brakes do not work so well; this is called ';brake fade';.


Modern brake systems and linings are not so susceptible as they used to be, but ';sporty'; drivers should still bear the effect in mind.


I'm not sure of the surface physics involved - possibly melting of points of roughness on a microscopic scale?How does change in temperature of an object affect its friction?
Temperature make atoms more energetic which excite electrons. As a result atomic and moleuclar size will increase which causes change in overall microscopic structures so therefore will affect the way in which it is in contact with another material. Like a jigsaw puzzle, only at certain sizes would the edges fit nicely together (increase in friction) and those sizes that do not fit would slide away (decrease in friction).





In the real world, there will inevitably be other substances existing in between the objects, like grease, wax and moisture for example. A small temperature increase is known to melt waxy substances and a cold temperature could freeze moisture microscopically. These factors will need to be considered.
yes it effects


it can be measured experimentally


increase in temperature will increase the vo;ume and hence the microscopic groves and depressions on the surface of the object will grow and hence friction will increase.
with a liquid, temperature affects its viscosity or density. Oil for instance becomes thinner with heat or thicker with cold.