Alift up system is used to transport objects among different floors. the two bearings on both ends of the shaft have the same dimension (l = 1 inch and diameter d = 2 inch), and they are made of steel-backed, ptfe coated bronze. the load bearing statistics are as follows: pmax = 36,000 psi; vmax = 390 ft/min; (pv)max = 51,000 lb-ft/in2-min. a cable is located at the midpoint of the shaft that is used to lift the chamber. the radius of the drum on the shaft is 6 inches. if the speed of the lifting chamber is 18 in/s, find the maximum load this lifting system can support.