Chapter 6, Problem 4Q

In three experiments, three different horizontal forces are applied to the same block lying on the same countertop. The force magnitudes are F₁ = 12 N, F₂ = 8 N, and F₃= 4 N. In each experiment, the block remains stationary in spite of the applied force. Rank the forces according to (a) the magnitude f_s of the static frictional force on the block from the countertop and (b) the maximum value ƒ_{s, max} of that force, greatest first.