Question

A 24-N horizontal force is applied to a 40-N block initially at rest on a rough horizontal surface. If the coefficients of friction are µs = 0 .5 and µk = 0 .4, find the magnitude of the frictional force on the block.

Answer 1

frictional force on the block:

$F_{fr}=\mu_{k}mg=0.4\cdot40=16$ N

where $\mu_k$ is coefficient of kinetic friction.