Question

1. Two boxes are stacked on a frictionless table. M. = 4kg and M, 5kg. The coefficient of friction between the boxes is such that when a 27 N force F is applied to the lower box, the boxes start to slip relative to each other. The system is then restored to rest and force F is removed. A horizontal force F is now applied to the upper box. What is this force's maximum value in order for the two boxes to slide together on the table without relative slipping? ma тв 2. A bead slides on a frictionless spoke of a wheel, which spins at a constant 0 =w. At time t =0 the radial velocity r = 0 and radial position is ro. (a) Write down force equations in polar coordinates for the bead. Note that there is no total nct force in the i direction. (b) Solve the 2nd order differential equation in the radial direction to find r(t). Use Mathematica or talk with me if you haven't learned this yet. (c) Use your result from part b to find the force on the bead in the direction. (d) Add a resistive force F, = -2kmrn to the spoke and re-solve for r(t). Take the limits of k → 0 and k → and look at the behavior of the bead in each case.

Answer 1