This discussion centers on the mechanics of preloading pulleys, specifically analyzing the effects of tensions T1 and T2 on angular velocity. It is established that the two scenarios presented—one with T1 and T2 applied to a pulley and another with T2 preloaded—are not equivalent due to differing torques. The participants clarify that the systems resemble spools fixed in space, free to rotate, and emphasize the importance of considering the net forces acting on the system. The conversation concludes that the tension on T1 is determined by the difference T1-T2, contingent on how T2 is applied.
PREREQUISITESMechanical engineers, physics students, and anyone interested in the dynamics of pulley systems and rotational mechanics will benefit from this discussion.
Hi Russ, you are correct. These are better described as spools fixed in space, but free to rotate around the point at the center of the circle. Let's say that they are bearings, sitting on shaft. In the left picture, the tension on T1 will simply be T1-T2. What will the tension on T1 be in the picture on the right.russ_watters said:
In that case, there's an additional force missing from the pictures, one that acts at the center and opposes the net force of the applied T1 and T2.PaulB said:
I think you tripped over your wording there. I think you mean to ask about the force on the center bearing? T1 and T2 are applied forces, right? The force applied by the bearing is T1-T2, yes. For the second one, it's the same as long as T2 is somehow applied to the spool and not the fixt point directly. Otherwise T2 isn't really doing anything.PaulB said: