What was the average coefficient of friction

The static coefficient of friction is the coefficient of friction that applies to objects that are motionless. The kinetic or sliding coefficient of friction is the coefficient of friction that applies to objects that are in motion. The coefficient of friction is not always the same for objects that are motionless and objects that are in motion; motionless objects often experience more friction than moving ones, requiring more force to put them in motion than to sustain them in motion.

Most dry materials in combination have friction coefficient values between 0. Values outside this range are rarer, but teflon, for example, can have a coefficient as low as 0. A value of zero would mean no friction at all, which is elusive at best, whereas a value above 1 would mean that the force required to slide an object along the surface is greater than the normal force of the surface on the object.

We have written many articles about the coefficient of friction for Universe Today. Jane Wang, Yip-Wah Chung. Contents Search. Friction Coefficient. Authors Authors and affiliations Peter J. How to cite. The normal force acts perpendicular to the interface between the bodies and is sometimes referred to as the load , particularly when it is applied downward, in the direction of gravity.

The equation is. The applied force on the block, Fapplied, is the pull from the string cause by the weight of the hanging mass, m. Now, calculate the friction force, f, the difference between the applied force and the net force. The equation is:. Graph the friction force, f, on the y-axis against the normal force, N, on the x-axis.

The slope will give you the kinetic friction coefficient. Place the object on the track at one end and slowly lift that end to make a ramp. At this angle, the effective force of gravity acting down the ramp is just barely greater than the friction force preventing the block from beginning to slide. Ariel Balter started out writing, editing and typesetting, changed gears for a stint in the building trades, then returned to school and earned a PhD in physics.

Since that time, Balter has been a professional scientist and teacher.