Dynamics: Kinetic Friction

Question

The coefficient of kinetic friction between an object and the surface upon which it is sliding is 0.43. The mass of the object is 4.1kg. What is the force of friction? 

Answer 1

The force due to friction is equal to the coefficient of kinetic friction * normal force.

Here the coefficient of kinetic friction = 0.43

The normal force here since we are assuming the object is sliding on a flat surface would be mass*acceleration due to gravity

Normal force = 4.1 kg * 9.8 m/s^2 = 40.18 kg*m/s^2 = 40.18 N

So the force due to friction will be equal to 0.43*40.18N = 17.28N = 17N (2 sig figs)