When objects are at rest on each other (i.e. static friction) their microscopic irregularities can settle into each other - and can also form electrostatic bonds.
static usully greater then kinetic
coefficient kinetic
Usually static.
The static coef. of friction is greater than the kinetic coef. of friction.
No, it CAN'T be greater, and it is usually smaller.
static usully greater then kinetic
static friction is higher in most cases, if you're talking about the coefficient of static or kinetic friction
coefficient kinetic
Usually static.
The static coef. of friction is greater than the kinetic coef. of friction.
kinetic friction
Kinetic friction is the friction that applies when an object is moving; static friction is the friction that applies when the object is not moving. Static friction must always be greater than, or equal to, kinetic friction.
The coefficient of static friction is always larger because it takes more initial force to move an object that is at rest.
The coefficient of static or kinetic friction depends on the surfaces that are causing friction. The formula for it is: force of friction over normal force.
Typically not. However rolling friction is somewhat of a myth. Rolling friction is actually caused by static friction. There are really only two types of friction: Static and Kinetic. That's it! Rolling friction is caused by static friction and the coefficient of friction (which determines its strength) is dependent upon the two materials of interaction.
The rougher a surface is, the higher the coefficient of static and kinetic friction will be.
No, it CAN'T be greater, and it is usually smaller.