In a home laundry dryer, a cylindrical tub containing wet clothes is rotated steadily about a horizontal axis, as shown in Figure P6.50. So that the clothes will dry uniformly, they are made to tumble. The rate of rotation of the smooth walled tub is chosen so that a small piece of cloth will lose contact with the tub when the cloth is at an angle of 68. above the horizontal. If the radius of the tub is 0.330 m, what rate of revolution is needed?