Greetings again, first I am not a student. I am just a silly man who likes to make sure I understand what I am talking about. Help me verify this: Lets say I have a 1000 lb load. That would give me a mass equal to 1000/32 ft/s^2 or 31.25 (m=F/a) Now lets say I want to accelerate this load with a move profile of 0 to 4 in/sec in 100msec. That would yield an acceleration of 40 in/sec^2. To move this load at this acceleration vertically upward I would need a force of F-1000=31.25*40 or 2250 lbs. I would like to connect this load to a rope wrap around a pulley of 2.5 inches in diameter. Radius = 1.25 Would the torque required at the shaft of the pulley be 2250*1.25 or 2812.5 inch-lbs? If its this simple, understanding I am neglecting drags and frictions of some sort, why the need for moments of inertia? Lastly, according the right hand rule of the cross product in figuring torque. Why is the torque(rotational force) pointing in the z direction. I mean the torque at my wheels of my car propel my car forward, but text books make it appear as though the torque is pointing in the direction of the axis of rotation wouldn't that tend to push the wheels outward away from the vehicle which it doesn't. Thanks in advance.