Showing the concept of coefficient of friction.
Rubber wood coefficient of friction.
Hard plastic on dry wood.
Coefficients of friction range from near zero to greater than one.
Static friction results from the normal force of two objects in contact acting opposite the intended motion of one surface against the other.
The coefficient of friction is the ratio of a force to a force and hence has no units.
The friction force is the force exerted by a surface when an object moves across it or makes an effort to move across it.
The dynamic coefficient of friction are.
Soft plastic on dry concrete.
N normal force between the surfaces n lb there are at least two types of friction forces.
Hard plastic on dry concrete.
Now slowly increase the angle of the ramp until the rubber just begins to slip.
A good way to determine the coefficient of friction is to do a test with the actual materials.
F f frictional force n lb.
The static and kinetic friction coefficient values reference table shown in this article will be helpful for finding the cof values of commonly used materials.
The maximum force of static friction can be calculated by multiplying the normal force by the coefficient of friction specific to the pair of materials in contact.
The value of μ s is generally higher than the value of μ k for a given combination of materials.
The coefficient of static friction typically denoted as μ s is usually higher than the coefficient of kinetic friction.
Soft plastic on dry wood.
Static friction is friction between two or more solid objects that are not moving relative to each other.
Where μ s is the coefficient of static friction and μ k is the coefficient of kinetic friction.
Soft rubber on dry concrete.
Hard rubber on dry wood.
F f μ n 1.
Static and kinetic coefficient of friction.
Hard rubber on dry concrete.
Typical values for the coefficient of friction when sliding is occurring i e.
The frictional force can be expressed as.
The friction force of a 100 lbwooden crate pushed across a concrete floor with friction coefficient of 0 62 can be calculated as.
Coefficients of friction between materials are best determined through testing.
For example ice on steel has a low coefficient of friction while rubber on pavement has a high coefficient of friction.
The coefficient of friction depends on the materials used.
For polished oiled metal surfaces less than 0 1.
For example static friction can prevent an object from sliding down a sloped surface.
For glass on glass 0 4.
μ static μ s or kinetic μ k frictional coefficient.
In your case build a ramp made of wood and place a sample of the rubber material on the ramp.
Soft rubber on dry wood.
