There are many useful application of friction, such as the brakes, clutches, belt drives, and the pulleys, etc. Friction comes into play between the brake pad and the rotating wheel of a bicycle helps to bring the bicycle to a stop when the pad is pressed against the wheel. The same principle applies to the braking in motor cars, however with continuous usage the surface of the pad becomes smooth due to wear. In this case friction between the pad and the wheel is less and it takes a longer distance to bring the moving bicycle or motor car to a stop, thus this can easily lead to an accident. Little wonder that mechanics check brake pads regularly for wear.
The belt drive which connects the engine pulley to the propeller shaft transmits part of the power generated by the engine to the propeller. This is made possible by virtue of friction between the belt surface and the groove in the pulley. Again with continuous usage the belt wears off, transmits power inefficiently and therefore has to be changed.
Other areas of applying of friction are in striking of a match by rubbing the head of the match stick against the rough side of a match box, and thus that will produce light.