Friction : A Necessary Evil
Recall now some of your experiences. Is it easier to hold a kulhar (earthen pot) or a glass tumbler? Suppose the outer surface of the tumbler is greasy, or has a film of cooking oil on it: would it become easier or more difficult to hold it? Just think : would it be possible to hold the glass at all if there is no friction? Recall also how difficult it is to move on a wet muddy track, or wet marble floor. Can you imagine being able to walk at all if there were no friction?If an object started moving, it would never stop if there were no friction. Had there been no friction between the tyres of the automobiles and the road, they could not be started or stoped or turned to change the direction of motion. You could not fix a nail in the wall or tie a knot. Without friction no building could be constructed.
Notes
Friction - Notes
