What causes friction?

Answer

The primary causes of friction are surface roughness, the plowing effect and molecular adhesion. Surface roughness is when serious abrasion occurs due to the roughness of the materials in contact. The plowing effect involves deformations of the objects that cause resistance to movement when the materials are relatively soft.

Adhesion refers to the molecular force that results from two materials brought into close contact with one another. To slide objects against each other, it is essential to break the adhesive bonds between them. According to recent scientific studies, friction occurs because of adhesive forces between materials. Ultra-smooth and sticky materials fall under the molecular adhesion category.

There are varying degrees of surface roughness in solid materials. Even a smooth surface has small bumps that interfere with sliding motion. When the surfaces of two hard, solid materials are very rough, friction occurs due to the abrasion that happens when two objects slide against each other.

Deformations are another cause of friction. Deformations form when soft materials deform under pressure and lead to an increase in resistance to motion. For example, when a person stands on a rug, he sinks in slightly, causing resistance as he drags his feet along the rug’s surface. Resistive force is created, and friction occurs when the deformation becomes large.

Q&A Related to "What causes friction?"
This may seem a simplistic issue on the surface, but it is one of the most common reasons for discord between couples. Smoking, drinking or leaving shoe brushes on the sofa or a lack
http://www.ehow.com/info_8385660_causes-friction-b...
its so stupid this website is stupid.
http://wiki.answers.com/Q/How_is_rolling_friction_...
The online music database Last.fm does not have a record of a band called Causing
http://www.chacha.com/question/who-is-the-band-cau...
While I can't say I can name all the reasons, here are a few... Historical antipathy between Arabs and Persians. This goes back at least to the late Roman period, when both Romans
http://www.quora.com/What-are-all-of-the-causes-of...
Explore this Topic
If you want to increase friction between to objects, you need to rub them together as fast as you can. Like rubbing your hands together will cause friction, and ...
Sliding friction is the kind of friction that is caused by two surfaces that slide against each other. This kind of friction is alternatively known as kinetic ...
To increase friction, you can make the surface of at least one object rougher. You can make one object heavier so that gravity causes a increase in friction. To ...
About -  Privacy -  Careers -  Ask Blog -  Mobile -  Help -  Feedback  -  Sitemap  © 2014 Ask.com