Question

The coefficient of kinetic friction between a wooden block and the wooden floor is 0.18. The mass of the

wooden block is 0.75 kg . Calculate the frictional force to start the wooden block in motion ?

Answer 1

Find the force of kinetic friction (force of friction that resists the motion of the block when we pull it):

$$F_k=\mu_k N=\mu_k mg=1.32\text{ N}.$$

All we can say about the force of static friction $F_s$, since we know nothing about the coefficient of static friction, is this:

$$F_s>F_k.$$