Effects of Friction

Friction can be very useful. Without it, you will not be able to walk steadily because your feet will keep on sliding on the floor or on the ground. In your physical education classes, you wear rubber-soled shoes to increase friction and prevent you from slipping off the smooth surface of the gymnasium. You can walk firmly with your leather shoes on rough surfaces.

Friction helps in stopping moving objects. For example, brakes use friction to slow down or stop moving vehicles because of the rolling resistance against the wheels. If you roll a ball in a flat area, it will stop eventually even without bumping on any object because friction exists between the ball and the ground.

At home, you experience friction in different ways. Friction helps you unscrew the tops or lids of bottles, jars, and cans. Twisting the tops of the jars to open them creates sliding friction between the surface of the top and your hands. In wood fixtures, static friction holds nails and screws in place. Friction is likewise used to make things smoother, as when sanding wood in pieces of furniture. When one scrubs a rough furniture with sandpaper, its surface becomes smooth because friction is present on the surfaces of the sand paper and the wood as they are rubbed together.

Friction also helps you identify objects and determine how these objects should be handled. When objects slip easily from your hand, it means that there is less friction between your hand and the object. In contrast, you can grip a rough object with ease because the high friction prevents it from slipping. Thus, touching objects not only helps you tell their textures but also gives you a clue to handle them tightly if the objects are slippery and not so tight if they are rough.

There is also friction between your hands when you rub them together. This friction, in turn, produces heat, making your hands feel hot. When you rub two sticks together, they will produce heat because friction occurs between them. When you rub the sticks together long enough, the heat produced by the friction may be sufficient to cause a spark and start a fire.

Friction has harmful effects too. Among these effects is that it wears away things. The tires of vehicles, as well as the shoes and clothes you wear, are worn away by friction. Moving and rubbing machine parts also wear away gradually because of friction.

You may hurt yourself or develop a bruise whenever your skin hits a rough surface or rub yourself against it. It is generally difficult for soft skin to resist a hard and rough surface. Friction also makes work harder at times, such as when moving a heavy appliance to another place. Additional force is required to overcome friction.