(Solved): 3. An electronic motor drives a machine through a speed-reducing gear ratio 11/1. The motor armatu ...

3. An electronic motor drives a machine through a speed-reducing gear ratio 11/1. The motor armature, with its shaft and gear wheel, has a moment of inertia 1 kgm by 0.5m. The rotating part of the driven machine has a moment of inertia of 20 kgm by 2m. The driven machine has a constant resisting torque of 120Nm and the efficiency of the reduction gear is 80%. a. What power must the motor develop to drive the machine at a uniform speed of 2.66667 rev/sec? b. The torque developed on the motor armature, in starting from rest, is 30Nm. What time will be required for the speed of the machine to increase from 0 to 1 rev/sec? c. If the Gear ratio were altered so as to give the machine the greatest possible angular acceleration in starting from rest, what will then be the gear ratio? The starting torque of the motor is 30Nm as before. (20 Marks)