Pulley suspending two different masses lifted upwards

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Homework Help Overview

The discussion revolves around a physics problem involving a pulley system with two different masses, m1 and m2, where m2 is greater than m1. The original poster seeks to determine the acceleration of each mass under different force conditions and the tension in the rope.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to analyze the system by considering the forces acting on the masses and the pulley. They express uncertainty about how to calculate acceleration and suggest treating the masses as a single unit initially.
  • Some participants question the clarity of the problem statement and the use of a template for providing necessary information, indicating that free-body diagrams could be beneficial for understanding the forces involved.
  • There is a discussion about the relationship between the acceleration of the masses and the conditions outlined in part A of the exercise.
  • One participant points out that the accelerations of the two masses may not be identical, prompting further clarification on variable definitions.

Discussion Status

Contextual Notes

Participants note the absence of a template that typically helps structure the problem statement and relevant equations, which may hinder the clarity of the discussion. There is also mention of the need for clearer definitions of variables used in the problem.

Sabatie
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Pulley with upward force.jpg
The force F pulls upwards two masses, m1 and m2(m2>m1), which are connected to each othet via a massless pulley. The masses are perched on the ground before movement starts.

A. What is the acceleration of each one of the respective masses in each of the following situations:
1)F<2*m1*g
2)2*m1*g<F<2*m2*g
3)2*m2*g<F

B. What is the rope's tension in each situation?

Though I'd viewed similar questions posted here, I couldn't draw any solution to this particular case involving as many parmeters as it does. Also, since, as I understand it, the heavier mass doesn't accelerate at all during the first stages of movement, but later does, I didn't grasp how to calculate the acceleration.
I assumed that I should first treat both masses as one, and then address each separately - though I wasn't sure how to proceed in that direction.
IMG_20150207_012054.jpg
(sorry for the inverted image)
Any help would be appreciated.

Thank you.
 
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Hello Sabatie, welcome to PF :)

Did you notice the template ? Pity it's gone now. It helps you to provide some essential information to potential helpers. I, for example, now have no idea whatsoever what you mean by a. The template provides space for all variables and given/known data. And I also have no idea if you know which equations you need to work out this exercise. The so-called Relevant equations.

1. The problem statement, all variables and given/known data
2. Relevant equations3. The Attempt at a Solution

Yes, there is something, but it now hangs loose in the air.
Which, as it happens, is a hint for you: make free-body diagrams for the three parts separately and then connect them.

On the bright side:
You are well under way. It's just that you haven't pinned down a. What is it and what is the relationship between your a and what is really asked for in part A of the exercise ? (Read it again, word for word...)
 
BvU said:
Hello Sabatie, welcome to PF :)

Did you notice the template ? Pity it's gone now. It helps you to provide some essential information to potential helpers. I, for example, now have no idea whatsoever what you mean by a. The template provides space for all variables and given/known data. And I also have no idea if you know which equations you need to work out this exercise. The so-called Relevant equations.

1. The problem statement, all variables and given/known data
2. Relevant equations3. The Attempt at a Solution

Yes, there is something, but it now hangs loose in the air.
Which, as it happens, is a hint for you: make free-body diagrams for the three parts separately and then connect them.

On the bright side:
You are well under way. It's just that you haven't pinned down a. What is it and what is the relationship between your a and what is really asked for in part A of the exercise ? (Read it again, word for word...)

Hello, and thank you for the welcome and reply. I apologize for not adhering to the template; I sincerely thought I had framed my question comprehensively.

Here are the diagrams:
2.jpg


I would appreciate it if you could shed some light on how I am to find the pulley's acceleration and, by doing so - find each body's acceleration(which are identical, since they move correspondingly).
 
Sabatie said:
find each body's acceleration(which are identical, since they move correspondingly).
No, the accelerations are different.
What is g'? Please define any variables that might not be self evident.
I can't quite make out some of your subscripts. The facility for posting images is not intended for handwritten text and equations, just diagrams.
 

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