Balancing on Pulley system

[curiousEngineer]

TL;DR Summary

Pulley balancing question

This is a basic conceptual question. Consider having a pulley mounted with identical mass of block A and B. If i pull the block A slightly by say 10mm, and then release it. Will these weights try to balance itself due to potential energy difference or will be in the same state?

 

[anuttarasammyak]

Say the rope has zero mass, total potential energy is constant during the process. If you pull 10 mm or with any other length, keep them at rest with your hand and release your hold, they balance there. If we cannot have zero mass rope, the downer side would go down more.

 

[kuruman]

Pull the block how? Sideways like a pendulum and release from rest or pull it down? If pull it down, release while the block is moving or stop the blocks and then release?

 

[curiousEngineer]

Pull the block how? Sideways like a pendulum and release from rest or pull it down? If pull it down, release while the block is moving or stop the blocks and then release?

Im pulling it down by 10mm, after small rest im releasing it again.

 

[curiousEngineer]

Say the rope has zero mass, total potential energy is constant during the process. If you pull 10 mm or with any other length and keep them at rest, they balance there. If we cannot have zero mass rope, the downer side would go down more.

Thank you for the explanation! Say there is friction also in the pulley. That will also affect this imbalance right?

 

[anuttarasammyak]

You refer friction. Both friction between rope and pulley and friction of pulley to rotate would matter.

 

[A.T.]

... the downer side would go down more.

True in many ways, but I think "lower side" fits better here.