Disk D turns with a constant clockwise angular velocity of 30 rad/s. Disk E has a weight o...

Disk D turns with a constant clockwise angular velocity of 30 rad/s. Disk E has a weight of 60 lb and is initially at rest when it is brought into contact with D. Determine the time required for disk E to attain the same angular velocity as disk D. The coefficient of kinetic friction between the two disks is μk = 0.3. Neglect the weight of bar BC.