Calculate the rms motor power for the following balanced dru

Calculate the r.m.s. motor power for the following balanced drum winder fitted with an equal mass tail rope and driven by a directly coupled electric motor.
Mass of mineral hoisted per wind, 1785 ton; mass of each empty cage and waggons, 2.68 ton; shaft depth, 640 m; height top cage position to headgear pulley, 27.5 m, distance headgear pulley to winding drum, 46 m; rope loop below bottom cage position, 15 m; winding drum diameter, 3.75 m; moment of inertia of all rotating parts, including12 rope on drum, 95 ton*m2; friction torque, 12 kN; rope mass 4.45 kg/m, acceleration time, 15 s, constant speed time, 55 s, retardation time, 15 s, loading and unloading time per cycle, 15 s.

Solution

The answer of following question is as follows..

The r.m.s of the given is 78 . I get this value while solving the problem