# Why doesn’t the coefficient of friction have units?

The slope has a physical meaning. Iti is called the coefficient of friction , greek symbol mu is an upside down u. the coefficient of friction essentially tells you howw much two surfaces stick together. Explain why the coefficient of friction does not have units

The coefficient of friction is a pure number without units (actually inches/inches which cancel). The coefficient can be determined in an experiment (see link) where a block of one material is placed on a hinged ramp made of the second material of interest. The ramp is slowly raised to an angle where the block just starts to slide. This forms a right triangle where the ramp is the hypotenuse and the height is one of the sides. The coefficient is calculated by dividing one side by another and the units cancel out.

There is no unit for coefficient of friction. For example, if the CoF is , just write:

• The coefficient of friction is a pure number without units (actually inches/inches which cancel). The coefficient can be determined in an experiment (see link) where a block of one material is placed on a hinged ramp made of the second material of interest. The ramp is slowly raised to an angle where the block just starts to slide. This forms a right triangle where the ramp is the hypotenuse and the height is one of the sides. The coefficient is calculated by dividing one side by another and the units cancel out.

Source(s): http://www.school-for-champions.com/science/experi…

• There is no unit for coefficient of friction. For example, if the CoF is , just write: