FRICTION

Posted under Latest posts on Sunday, 23 August 2009 by admin

Whenever two bodies are kept in contact, whenever either one or two of them move or tend to move,

they experience a force of friction.The force of friction is zero on smooth surfaces although no

surface is frictionless however smooth it may be. Friction is an evil but more necessarily a friend.

Many of them are of the opinion that friction is only a evil but it is more necessary, but how? it will

explained it further. Friction is a force which opposses the RELATIVE motion between two bodies in contact

. Why am i stressing the word relative here? Consider a system of bodies A and B, A tied to a wall as

as shown. Let B be pulled with a force.

When the body is pulled, B tends to move in the direction of application of the force,since A is

tied to the wall, it tends to remain at rest. The direction of motion of B is rightwards and hence the

direction of friction is leftwards, now consider the bodies A and B, B is tending move towards right,

since the motion of A is restricted, the direction of motion A with respect to B is leftwards and hence

the direction of friction is rightwards. But the motion of the whole system is rightwards, and friction

between A and B is also rightwards, this is aganist what is generally to be believed. Hence i stressed

on the word RELATIVE motion. Whenever there is a motion of two or more bodies in contact, the direction

of friction depends on the relative motion between the bodies and contact surfaces. The relative motion

and relative velocities deicides the magnitude and direction of the force of friction. Hence we must be

extra careful in deiciding the direction of frictional force in cases of relative motion.

Most of us think that friction is always an evil that causes energy loss and so on. But the picture of

this is completely different, this may be probably called as half knowledge or ignorance. Friction is

more of a friend rather than an evil. Friction is necessary to even start a machine in which friction

is supposed to cause energy loss in the same machine. Even in many transmission systems, method of

transmission is effective through friction, although it causes energy loss in the same transmission

systems.However it should be noted that friction can be reduced but cannot be made zero.Not necessary

that only in the above mentioned case, there are many cases that innolve the problems in finding out

the direction of friction which have relative motion in between them.There are cases such as man rowing

in a boat experiences problems due to the water current (discussed in detail in relative motion) and

also the direction of wind, which causes resistence in other words friction to motion of the boat.

Hence a person rowing in a particular direction may not reach his desired destination at all. Hence there

should be a proper approach, analysis and solution to practical problems involving relative motion.

Whenever two bodies are kept in contact, whenever either one or two of them move or tend to move,

they experience a force of friction.The force of friction is zero on smooth surfaces although no

surface is frictionless however smooth it may be. Friction is an evil but more necessarily a friend.

Many of them are of the opinion that friction is only a evil but it is more necessary, but how? it will

explained it further. Friction is a force which opposses the RELATIVE motion between two bodies in contact

. Why am i stressing the word relative here? Consider a system of bodies A and B, A tied to a wall as

as shown. Let B be pulled with a force.

friction

When the body is pulled, B tends to move in the direction of application of the force,since A istied to the wall, it tends to remain at rest. The direction of motion of B is rightwards and hence thedirection of friction is leftwards, now consider the bodies A and B, B is tending move towards right,since the motion of A is restricted, the direction of motion A with respect to B is leftwards and hencethe direction of friction is rightwards. But the motion of the whole system is rightwards, and friction between A and B is also rightwards, this is aganist what is generally to be believed. Hence i stressedon the word RELATIVE motion. Whenever there is a motion of two or more bodies in contact, the directionof friction depends on the relative motion between the bodies and contact surfaces. The relative motionand relative velocities deicides the magnitude and direction of the force of friction. Hence we must beextra careful in deiciding the direction of frictional force in cases of relative motion.Most of us think that friction is always an evil that causes energy loss and so on. But the picture ofthis is completely different, this may be probably called as half knowledge or ignorance. Friction is more of a friend rather than an evil. Friction is necessary to even start a machine in which frictionis supposed to cause energy loss in the same machine. Even in many transmission systems, method oftransmission is effective through friction, although it causes energy loss in the same transmissionsystems.However it should be noted that friction can be reduced but cannot be made zero.Not necessarythat only in the above mentioned case, there are many cases that innolve the problems in finding outthe direction of friction which have relative motion in between them.There are cases such as man rowingin a boat experiences problems due to the water current (discussed in detail in relative motion) andalso the direction of wind, which causes resistence in other words friction to motion of the boat.Hence a person rowing in a particular direction may not reach his desired destination at all. Hence thereshould be a proper approach, analysis and solution to practical problems involving relative motion.