2006-08-18 16:10:04 · 8 answers · asked by redeyes_kranti 2 in Science & Mathematics ➔ Engineering
friction is resisting force to the sliding pairs....
friction is directly proportional to the normal load between the surfaces of the given pair of materials...
it depends upon the material of which the contact surfaces are made (ie, the roughness of the material)....
finally, it is the force which opposes the sliding motion and it acts in the direction opposite to which the body tends to move...
hence, it is independent of the area of contact as well as sliding velocity...!!!
2006-08-20 15:11:12 · answer #1 · answered by Praful M Nimbargi 2 · 0⤊ 0⤋
Friction depends on the force of contact between the two surfaces, which is usually caused by gravity (in other words, the object's weight). If you have a large area of contact, the weight of the object is distributed more, and so any specific point has less pushing down on it. With a small area of contact, each point on the area of contact bears more weight. So if you have a greater area of contact, it would make sense that there is more friction, but since the weight is distributed over a wider surface, they cancel each other out, and only the force of contact matters. Air resistance, however, is an example of a friction force that 'does' depend on the area of contact, and the formula for air resistance includes speed and area, a totally different formula than most friction equations.
2006-08-18 16:22:12 · answer #2 · answered by Anonymous · 1⤊ 0⤋
It is an approximatiion that frictiion is proportional to the normal force and no other physical quantities. This is the first model that one learns in engineering physics, and it works fairly well for most contrived physics problems and rough calculation engineering problems. But, alas, all models have their limits. A practicing engineer will take into consideration the area of contact when designing for the effects of friction (and other things too...like the relative speed of the two objects, temperature, etc.)
2006-08-18 23:59:46 · answer #3 · answered by socrmom 2 · 1⤊ 0⤋
Actually, it does. But most physics and mechanical engineering students are sufficiently lost and confused that they don't really need to worry about 2'nd order effects concerning surface area, mass, and friction until they're in graduate school ☺
Doug
2006-08-18 16:19:11 · answer #4 · answered by doug_donaghue 7 · 1⤊ 0⤋
it is because friction always acts inbetween the two layers in contact.it is an opposing force which acts PARALLEL to the surface in contact.(it opposes the relative motion between the two surfaces) .so that is why it does not depend on the area of contact
2006-08-18 17:01:12 · answer #5 · answered by geeta m 2 · 0⤊ 1⤋
the easy thank you to think of of this one is, if I press one finger firmly onto a table perfect and then drag my finger alongside the table. The tension required to try this could be X. If despite the fact that I place my finished hand on the table and exert the comparable tension and then drag my hand around the table the for would be equivalent to X + added tension. In different words the huge the section it extremely is in touch the greater desirable the stress required to flow.
2016-12-17 13:26:00 · answer #6 · answered by shorb 4 · 0⤊ 0⤋
FRICTION is nothing but the resistance encountered when one body is moved in contact with another so due to this it is dependend on the area of contact.
2006-08-19 05:32:04 · answer #7 · answered by JEGADEV 1 · 0⤊ 1⤋
sorry but it is dependent on the area... the greater the area the greater the friction.. that is why the wheel. was invented
2006-08-18 16:17:09 · answer #8 · answered by wizard 4 · 0⤊ 2⤋