Question

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

Answer 1

Answer:

$\mu_k=\frac{a}{g}$

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 $\mu_k$:

$ma=\mu_k(mg)\\\mu_k=\frac{a}{g}$