plz answer this as soon as possible.Really urgent
2006-09-23 17:22:03 · 5 answers · asked by shafi 2 in Science & Mathematics ➔ Physics
No. The reason is that friction turns mechanical energy into heat. Now any time you turn energy into heat, you essentially lose that energy (some of it can be recovered by the use of a heat engine, but the efficiency of such devices is subject to fundamental limitations from the second law of thermodynamics). As such, generating friction as a means of creating power is invariably counterproductive. Now, there are a great many uses for friction in USING power (e.g. the friction of a car's tires against the ground means the car can actually move instead of just spinning it's wheels uselessly), but none whatsoever in generating it.
And as for the matchstick, the energy comes from the combustion of the wood. The only thing friction does is to convert the translational motion of the matchstick into a spark sufficient to ignite the phosphorus, which in turn lights the match. The friction does not serve as an energy source in this cycle.
2006-09-23 17:35:26 · answer #1 · answered by Pascal 7 · 0⤊ 1⤋
A method of welding uses friction force. Principally, they fasten parts on two motors and then switch on the motors. By contacting the rotating parts, large amount of heat melts the welding areas. Finally, they stop the parts and let the molten areas mix and then be cooled.
2006-09-23 17:33:30 · answer #2 · answered by Farshad 2 · 1⤊ 0⤋
Friction is not by any means an energy source.
2006-09-23 20:41:37 · answer #3 · answered by Frank N 7 · 0⤊ 0⤋
Brakes.
They use friction to impart a force opposite the direction of travel of a car. And they are quite common
2006-09-23 17:37:18 · answer #4 · answered by Jason 5 · 0⤊ 0⤋
On what scale, like major industrial, or what?
2006-09-23 17:33:23 · answer #5 · answered by YeahWellYouKnowHowItIs 2 · 0⤊ 0⤋