What are two properties of friction?

1. It always acts in the direction opposite to the direction of motion. 2. It's magnitude is equal to that of the force trying to set the object in motion only until it starts to move. Once the object starts to move the force is constant. read more

The friction level may be permanently altered causing hardening, cracking, flaking, and charring or even burning of the linings or pads. If the thermoplastic binder resins are used with the lining or pads a deposit may form on the rubbing surfaces, which may change the friction properties of the material (Fig. 28.32). Resistance to Wear. read more

When two surfaces are sliding across each other, the amount of kinetic friction present can be calculated using the equation f k = µ k N where µ k is the coefficient of kinetic friction and N is the net force normal. read more

Properties of Friction. Experiment shows that when a dry and lubricated body presses against a surface in the same condition, and a force F attempts to slide the body along the surface, the resulting frictional force has three properties. Property 2. read more