The figure shows a preliminary conceptual idea for a device to exert a braking force on a...

The figure shows a preliminary conceptual idea for a device to exert a braking force on a rope when the rope is pulled downward by the force T. The coefficient of kinetic friction between the rope and the two bars is μk = 0.28. Determine the force T necessary to pull the rope downward at a constant rate if F = 10 lb and (a) α = 30°; (b) α =20°.