Dynamics: Kinetic Friction

Question

The coefficient of kinetic friction between an object and the surface upon which it is sliding is 0.28. The weight of the object is 30N. What is the force of friction?

Answer 1

F_F = μN where F_F is the force of friction, μ is the coefficient of friction and N is the Normal force (which for a flat surface is equal to the object's weight).

So F_F = (0.28)(30) = 8.4 N