Coupon Accepted Successfully!



Contact Forces are types of forces in which the two interacting objects are physically contacting each other. Examples of contact forces include frictional forces, tensional forces, normal forces, air resistance forces, and applied forces.

Frictional forces are present everywhere in our daily life. It is simply impossible to reduce them completely. Frictional forces are equally useful in some situations as they are a hindrance in others.

Whenever two things rub together, some of the energy they have is lost to overcome friction. Basically, in things like car engines, the wheels of your skates, and the chain of your bike, friction is a force that slows you down. In order to overcome friction, you have to work harder. However, the energy doesn't just disappear it's turned into heat!

Try rubbing your hands together as fast as you can. Pretty soon, they'll be burning up!


As it turns out, the rougher two surfaces are, the more friction there is between them when they rub together. By making things really smooth, or by adding lubricants like grease and oil, engineers work hard to reduce friction and in the long run, save energy.

Without friction the wheels of a locomotive could not "grip" the rails nor could power be transmitted by belts.

On the other hand, in the moving parts of machines a minimum of friction is desired; an excess of friction produces heat, which in turn causes expansion, the locking of the moving parts, and a consequent breakdown of the machinery.

Test Your Skills Now!
Take a Quiz now
Reviewer Name