Does the force of kinetic friction depend on the weight of the block? Does the coefficient of kinetic friction depend on the weight of the block?
2007-10-12 05:58:55 · 6 answers · asked by Natiphy2007 1 in Science & Mathematics ➔ Physics
1. It can in practice but doesn't logically need to.
2. Yes
3. It can in practice but doesn't logically need to.
2007-10-12 06:21:27 · answer #1 · answered by Dr. R 7 · 0⤊ 0⤋
No it does not. Kinetic friction is a force of friction agings the motion of the moving block. f=uN f -force of friction u - coefficient of kinetic friction N normal to the surface force generated by the weight of the block and perpendicular to the surface. However, at the extreme, if the block is being moved too fast 1. the surface of the block the one that rides on the surface will heat up and may even burn. That would change the coefficient of friction. or 2. The block may start to float as if on a cushion of air. That would make the coefficient of friction almost zero.
2016-05-22 02:19:40 · answer #2 · answered by cari 3 · 0⤊ 0⤋
No. The coefficient of kinetic friction is independent of either the weight or the speed of the moving bloc. In most workable models in physics, some initial conditions are idealized. In this case, for most problems that you will encounter, the standard model of friction is the assumption. Under such model, the coefficient of kinetic friction depends only on the roughness of the supporting surface.
Dan B
2007-10-15 05:19:32 · answer #3 · answered by Dan Baneni 1 · 0⤊ 0⤋
The coefficient of kinetic friction is slightly less than the static friction and hence it depends upon the nomal reaction, ie weight of the block.
The coefficient of kinetic friction is constant for a very large range of velocities. Hence we can consider it as independent of velocitiy if the velocity is not very high.
2007-10-12 08:51:28 · answer #4 · answered by Pearlsawme 7 · 1⤊ 0⤋
No. It depends only on the natural force, that is the force pushing the object to the surface.
Try it. Drag your hand(or a book) across a desk. Now add some wait or push down on the book. Now try it again this time moving the book faster. You will notice speed has nothing to do with friction. In fact, the equation for friction is F=kN, F being the force of friction, k being the coefficient of friction, and N being the force pushing the object to the surface.
2007-10-12 06:03:46 · answer #5 · answered by Kazel 2 · 0⤊ 2⤋
COF for any two materials depends on system variables like temperature, speed, atmosphere, as well as on geometric properties of the interface between the materials
If you try to slide a heavy box resting on the floor, you may find it difficult to get the box moving. Static friction is the force that is counters your force on the box. If you apply a light horizontal push that does not move the box, the static friction force is also small and directly opposite to your push. If you push harder, the friction force increases to match the magnitude of your push. There is a limit to the magnitude of static friction, so eventually you may be able to apply a force larger than the maximum static force, and the box will move. \
Once the box starts to slide, you must continue to exert a force to keep the object moving, or friction will slow it to a stop. The friction acting on the box while it is moving is called kinetic friction. In order to slide the box with a constant velocity, a force equivalent to the force of kinetic friction must be applied. Kinetic friction is sometimes referred to as sliding friction.
2007-10-12 06:03:20 · answer #6 · answered by Anonymous · 1⤊ 1⤋