Finding the Acceleration of masses on a pulley

AI Thread Summary
The discussion revolves around calculating the accelerations of two connected masses, M and m, in a pulley system. It emphasizes that both masses will have the same magnitude of acceleration due to their connection via strings. A key point raised is the condition under which mass M can ascend while mass m descends, which requires analyzing the equilibrium state of the system. The initial attempt at solving the problem incorrectly treated the masses separately, highlighting the importance of understanding their interdependence. Overall, the conversation underscores the need for a conceptual grasp of the system's dynamics and equilibrium conditions.
rodrale25

Homework Statement


Masses M and m are connected to a system of strings and pulleys as shown
in the diagram below. The strings are massless and inextensible, and the p
ulleys are massless and
frictionless.
A: Find the accelerations for M and m (Hint: Think about these two questions:
Do these two masses have the same accelerations
in magnitude ? How is the distance that the lower pulley moves related to the distances
that masses M and m travels?)

B: One can imagine that when M is much larger than m, mass M would descend while mass m w goes up. Under what condition for M and m, would mass M go up while mass m descend? Explain your reasoning by considering the static situation (i.e., when the two masses are in equilibrium with neither M nor m moving)

Homework Equations


Sum of Forces=ma[/B]

The Attempt at a Solution


I said F= the sum of forces for just one of the masses and solved for a. Doing this for both masses, I got two separate accelerations, and then I realized that the two masses are connected. I know this isn't right because the two masses are connected by the strings somehow but I can't conceptually picture this.[/B]
 

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Hello Rod, :welcome:
rodrale25 said:
I know this isn't right because the two masses are connected by the strings somehow but I can't conceptually picture this
For this reason you are given hints in the form of two questions. What are your answers?
You get a third one from me :smile: : can you imagine an equilibrium situation ? If so, under what condition ?
[edit] reading ahead can be profitable (for folks like me too :rolleyes:): the same question is asked in part B.
 
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