- #1
ahmed11
- 83
- 0
if i have two cylinders with same mass and radius placed over each other vertically and there is a motor inside the top cylinder welded in the cylinder itself, and connected to the bottom cylinder to rotate the bottom cylinder. assume it's the whole thing is resting on the ground and neglect friction with ground. if i try to calculate the moment of inertia of the bottom cylinder for the motor to rotate should i put the mass of the bottom cone only or add the mass of the whole thing? and if yes add all the mass, how to manipulate the whole thing to make the motor rotate the bottom cylinder instead of the top one. what i have in mind is if the mass of top cylinder with motor is 10 kg and bottom is 5kg i just have to change the length of lever which is between motor and top cylinder and make it shorter than the lever in the bottom cylinder between the shaft of motor inside the bottom cylinder welded to the walls of bottom cylinder so actually changing the radius of the bottom cylinder. Hope this makes sense