Two identical tubes A and B are suspended by two identical wires (O-D and 0-E) that are attached to a hook on a ceiling. The radius and weight of each

tube are r and w, and the wire length is 3r.A third tube, C, is added on top of the two identical tubes as shown in the figure. Assume that the contacts between the tubes are frictionless. a) Find an expression, wcmax (r, w), for the largest weight that tube C can have before equilibrium conditions are violated. b) When r =0.5 m and w =10 kg, determine the corresponding Wc,max: c) Take r = 0.5 m, w = 10 kg, and wcmax from b). Determine the diameter of the wires so that their normal stress o = 50 MPa.