The robotic device of Prob. 6/67 is repeated here. Member AB is rotating about joint A with a counterclockwise angular velocity of 2 red/s, and this rate is increasing at 4 red/s2 Determine the moment MB exerted by arm AB on arm BC if joint B is held in a locked condition. The mass of arm BC is 4 kg, and the arm may be treated as a uniform slender rod.