Just realized the answer...sorry.
Why does friction cause heat?
- Thread starter chiddler
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Share please. The only answer I have is that the kinetic energy needs to be lost to some other form of energy given the law of energy of conservation. Beyond that I have nothing.
Heat is the sum of all the kinetic energies of molecules within an object.
Friction takes the translational kinetic energy of a moving object and transfers it into movement of individual molecules that are on the surface of the objects that are in contact with each other.
Friction takes the translational kinetic energy of a moving object and transfers it into movement of individual molecules that are on the surface of the objects that are in contact with each other.
yes.
If it helps, MedPR, my fallacy was thinking that friction caused transfer of energy from one body to another. I began pondering: if both bodies are at 0k, is there no friction?
It doesn't. Friction is transfer of energy from the energy exerted on one body to both interacting bodies in the form of thermal energy. In other words, heat is generated not transferred. So even if both bodies are at 0k, the friction is a result of the energy you exert on one of the bodies.
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I think this is one of those meaning of life questions like "What causes gravity?" and "Why is the Earth flat?" We can do all sorts of math to keep track of the thermal energy dissipated by kinetic friction, but exactly why it happens is perhaps best answered by "it just does." I guess a good visualization is that of a flat object sliding across a gooey surface where it sticks momentarily, slowing it down. Once it breaks free of the goo, the goo molecules that were stretched away by the sliding object are free to vibrate and in doing so heve thermal energy (in the form of vibrational kinetic energy).
