Recall that the formula for the maximum friction is $$F_f = \mu N$$, where $$\mu$$ is the co-efficient of friction, and $$N$$ is the normal force.
What is the force of friction on an object, if $$\mu = 0.1, \, N = 10 \, \mathrm{N}$$? The object is not moving and no force is being exerted on it.
• $$0.1 \times 10$$
• $$0.1 \times 20$$
• $$0$$