a. A large box of mass M is moving on a horizontal surface at speed v₀. A small box of mass m sits on top of the large box. The coefficients of static and kinetic friction between the two boxes are μ_s and μ_k, respectively. Find an expression for the shortest distance d_min in which the large box can stop without the small box slipping.

b. A pickup truck with a steel bed is carrying a steel file cabinet. If the truck’s speed is 15 m/s, what is the shortest distance in which it can stop without the file cabinet sliding?