Pulley suspending two different masses lifted upwards

In summary, Sabatie attempted to solve a problem involving masses and a pulley, but was not able to provide a solution. He did, however, provide a summary of the conversation.
  • #1
Sabatie
2
0
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 seperately - 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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  • #2
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...)
 
  • #3
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).
 
  • #4
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.
 

Related to Pulley suspending two different masses lifted upwards

1. How does a pulley work in lifting two different masses upwards?

A pulley is a simple machine that consists of a wheel with a groove around its circumference and a rope or chain running through it. When used to lift two different masses, the pulley allows the force to be distributed between the two masses, making it easier to lift them upwards. As one mass goes down, the other goes up, reducing the overall force needed to lift both masses.

2. What is the mechanical advantage of using a pulley to lift two different masses?

The mechanical advantage of a pulley is the ratio between the amount of force applied and the amount of force needed to lift the load. In the case of a pulley suspending two different masses, the mechanical advantage is equal to the number of ropes supporting the masses. For example, if there are two ropes supporting the masses, the mechanical advantage is 2, meaning that the force needed to lift the masses is half of the total weight of the masses.

3. How does the mass of each object affect the movement of the pulley system?

The mass of each object affects the movement of the pulley system by increasing or decreasing the amount of force needed to lift them. The heavier the masses, the more force is needed to lift them. Additionally, the difference in mass between the two objects will determine the direction in which the pulley will move. The heavier object will move downwards while the lighter object moves upwards.

4. What factors affect the efficiency of a pulley system in lifting two different masses?

The efficiency of a pulley system in lifting two different masses is affected by several factors. These include the number of ropes supporting the masses, the angle of the ropes, the weight and friction of the pulley, and the weight and friction of the objects being lifted. Additionally, the placement of the pulley in relation to the masses can also affect its efficiency.

5. Can a pulley system be used to lift two different masses with equal weights?

Yes, a pulley system can be used to lift two different masses with equal weights. In this case, both masses will have the same amount of force acting on them, making it easier to lift them. However, it is important to note that the mechanical advantage of the pulley system will be reduced since the force needed to lift the masses will be equal to the total weight of the masses.

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