This demo shows the difference between the static friction coefficient and the kinetic friction coefficient. The static friction coefficient is always greater than the kinetic friction coefficient, meaning it will take a greater force to begin to move the block than it will to continue to accelerate the block once it has begun moving. At this point, in order to keep the block moving at a constant speed, you will only need to apply a force equal to that of the friction force experienced by the block.
Skip to toolbar Log In Search. Does plastic have more or less friction than carpet? The kind of friction that results when you rub sandpaper against wood?
What kind of friction results when you rub sandpaper against wood? How do you raise and lower frictional forces? How does sandpaper have so much friction? Why does it take more force to slid a heavy box across carpet that it does to slide it across a tiled floor? Does lubrication increase friction? Why does a carpet have more friction than linoleum flooring?
What is example of sliding friction? Examples of high friction? What objects causes high friction? How does sandpaper slow thing down? Why does carpet have so much friction? How does carpet affect a rolling ball? Why does a block of wood get warm when it is rubbed with sandpaper? People also asked.
What is the perimeter of a 3ft wide and 5ft long rectangle? View results. What does have more friction doormat or carpet? Study Guides. Trending Questions. Still have questions? Find more answers.
The causes of this resistive force are molecular adhesion, surface roughness, and deformations. Adhesion is the molecular force resulting when two materials are brought into close contact with each other. What surfaces have less friction? A smooth surface has smaller hills and valleys. There are also electrostatic attractions between surfaces, but these are weaker than the physical barriers to sliding. Liquids such as water and oil reduce friction because they keep the two surfaces from contacting each other.
What materials produce less friction friction? Concrete on concrete has a very high coefficient, and Teflon on most things has a very low coefficient. Teflon is used on surfaces where we don't want things to stick; such as pots and pans.
Scientists have discovered that there is even less friction in your joints than in Teflon! Why does carpet have a lot of friction? Did the quarters go farther on the smooth wooden surface or on the carpet? This occurs because there is much more friction between the stack of quarters and the carpet's rough surface than there is between them and the smooth surface of the wood.
What is friction force examples? Specific examples of sliding friction include: Rubbing both hands together to create heat. A sled sliding across snow or ice. Skis sliding against snow. The model of molecular cohension tried to explain this effect by describing friction as the cohesion of molecules between surfaces.
The molecules of one substance would have to come close enough to the molecules of the other substance to interact. These contact points should produce some type of wear. This model was proven wrong when Jacob Israelachvili found clear evidence for a wear-free friction in the 's. The current model used to explain wear-free friction is based on the vibrations of atomic lattices. The basic concept is friction occurs when atoms close to one surface are set in motion by the sliding action of atoms in the opposing surface.
These vibrations are called phonons which are really sound waves which eventually get converted into heat. The amount of mechanical energy the energy needed to keep the object moving converted to phonons depends on the nature of the sliding substance because different solids vibrate a certain specific frequencies.
If one solid has many of the same frequecies as another then friction will be high. An excellent discussion of this can be found in Scientific American pg. Another older but still informative article can be found in Scientific American pg. Normally, this does not effect simple physics experiments because as the load increases the surfaces flattens out and the contact area increases proportionally.
Additionally, conjecture 4 is only approximately true for medium velocity experiments.
0コメント