Determine the speeds of the 2 masses

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The discussion revolves around the initial potential energy of a pulley in a physics problem involving two masses. Participants clarify that potential energy values are arbitrary, emphasizing that only differences in potential energy are significant for calculations. The initial potential energy of the pulley can be set to zero without affecting the outcome, as its height remains constant. Assigning a non-zero potential energy would not change the final results since it would cancel out in the equations. The key takeaway is that the choice of reference point for potential energy does not impact the analysis of the system.
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Homework Statement


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Homework Equations

The Attempt at a Solution


Here is the solution in the answers sheet. Why the initial potential energy of the Pulley (M) = 0?

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The initial potential energy is not zero in the calculation.

It would not matter - potential energies are arbitrary, only differences in potential energy (before/after) matter. The difference is not zero.
 
mfb said:
The initial potential energy is not zero in the calculation.

It would not matter - potential energies are arbitrary, only differences in potential energy (before/after) matter. The difference is not zero.
you don't get what I mean.
He put the potential zero of the pulley =0. Why is that? The pulley is at a height so it accuires potential energy.
 
Ah, that.
Same thing: It does not matter, as its height does not change. Any potential energy you assign to it would appear on both sides of the equality, and cancel.
 

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