Friction

Reducing the amount of friction in a machine increases the machine’s efficiency. Less friction means less energy lost to heat, noise, and wearing down of material. People normally use two methods to reduce friction. The first method involves reducing the roughness of the surfaces in contact. For example, sanding two pieces of wood lessens the amount of friction that occurs between them when they slide against one another. Teflon creates very little friction because it is so smooth.

Applying a lubricant to a surface can also reduce friction. Common examples of lubricants are oil and grease. They reduce friction by minimizing the contact between rough surfaces. The lubricant’s particles slide easily against each other and cause far less friction than would occur between the surfaces. Lubricants such as machine oil reduce the amount of energy lost to frictional heating and reduce the wear damage to the machine surfaces caused by friction.