posted by Hanu .
a) Why are there no units attached to values of μ?
b)A force of 120 N is needed to push a box along a level road at a steady speed. If the force of gravity on the box is 250 N, what is the coefficient of kinetic friction between the box and the road?
because it is a ratio of friction force to normal force
see answer to a above
friction force / normal force = 120/250