Friction Vs. Gravity

Difference Between Friction And Gravity
Friction and Gravity
If you think about it for a minute, you will realize what causes this resistance. The bicycle’s wheels rub on their axles; the ground rubs on the bicycle’s tires; and the air rubs on you and the bicycle as you force your way through it. This rubbing action is called friction. Friction is always with us, resisting our efforts to keep things moving. There are ways of reducing friction. The ball bearings in bicycle wheels reduce friction. Friction can be reduced further by keeping the tires fully inflated so that there is as little contact as possible between them and the ground. But there is no way to get rid of friction altogether. Friction is one of the things you must work against every time you apply a force to move an object from one place to another.
A great deal of work is done against gravity. Gravity is a force that pulls objects toward the center of the Earth. When you lift a book from the table, you are working against the force of gravity, which pulls the book downward. As you try to raise the book, you must apply an upward force to overcome the downward force. When the book moves in the direction of this upward force, you may say that you have worked to raise the book.
Friction and gravity are two of the natural forces that oppose us in almost everything we do. Much work is done against friction or gravity—or against both at the same time. For example, if you pedal a bicycle along a level road, you are working against friction only. When you lift a bicycle straight up to put it in a rack on top of a car, your work is being done mostly against gravity. When you pedal a bicycle up a hill, you are working against both friction and gravity.