Question

A block with mass m is pulled horizontally with a force F_pull leading to an acceleration a along a rough, flat surface.

Find the coefficient of kinetic friction between the block and the surface.

Answer 1

`\mu_k=(a)/(g)`

Step-by-step explanation:

The force of kinetic friction on the block is defined as:

`F_k=\mu_kN`

Where
`\mu_k` is the coefficient of kinetic friction between the block and the surface and N is the normal force, which is always perpendicular to the surface that the object contacts. So, according to the free body diagram of the block, we have:

`N=mg\\F_k=F=ma`

Replacing this in the first equation and solving for
`\mu_k`:

`ma=\mu_k(mg)\\\mu_k=(a)/(g)`