Newton's laws of motion -- pulley system

[Vv anand]

Homework Statement

In the situation given all surfaces are friction less pulley is ideal and steering is light. Find accn of block 2

Homework Equations

Given F=mg/2

The Attempt at a Solution

.[/B]
Got answer as G/2 instead of G/4 ...(actual answer is g/4)
Since F=mg/2 and block 1 is hanging so acceleration shld be g/2 of block 1 and therefore acceleration of Block 2 shld g/2.

 

[Orodruin]

i do not understand your argumentation. Can you spell it out with more detail?

The correct answer is g/4.

 

[Vv anand]

Yes sure...Im not getting the answer as g/4... instead I am getting g/2 ...i am maybe wrong at some point but i can't figure out where

 

[Vv anand]

i do not understand your argumentation. Can you spell it out with more detail?

The correct answer is g/4.

Yes sure...Im not getting the answer as g/4... instead I am getting g/2 ...i am maybe wrong at some point but i can't figure out where

 

[Orodruin]

Yes sure...Im not getting the answer as g/4... instead I am getting g/2 ...i am maybe wrong at some point but i can't figure out where

Yes you are wrong, which is why I asked you to expand your reasoning so that it might be apparent where your logic fails. As it stands, it is very difficult to follow your logic.

 

[Vv anand]

Yes you are wrong, which is why I asked you to expand your reasoning so that it might be apparent where your logic fails. As it stands, it is very difficult to follow your logic.

Oh ok sure,My logic say that acceleration of pulley equals acceleration of the block 2(pic) and acceleration of pulley is a2-a1 but this gives me answer as g/2..

 

[Vv anand]

Oh ok sure,My logic say that acceleration of pulley equals acceleration of the block 2(pic) and acceleration of pulley is a2-a1 but this gives me answer as g/2..

But this logic is incorrect right?

 

[Orodruin]

What is a1 and a2? You mist define things before you can use them. What are they and what values would they take. Please work on spelling out your thoughts. You have so far just briefly described your thoughts, not really motivated why you think some relations should hold.

 

[Vv anand]

What is a1 and a2? You mist define things before you can use them. What are they and what values would they take. Please work on spelling out your thoughts. You have so far just briefly described your thoughts, not really motivated why you think some relations should hold.

a2 is the force and a1 accn of block 1
I think that since surface is massless the magnitud that pulley accelerate will be same as the magnitude block 2 accelerates since there are no other force acting on the body..

 

[Vv anand]

a2 is the force and a1 accn of block 1
I think that since surface is massless the magnitud that pulley accelerate will be same as the magnitude block 2 accelerates since there are no other force acting on the body..

Can you please explain your logic...i m pretty confused after this

 

[Orodruin]

a2 is the force and a1 accn

Let me stop you right there. Force and acceleration have different physical dinension. It makes no sense whatsoever to take a difference between a force and an acceleration.

I think that since surface is massless the magnitud that pulley accelerate will be same as the magnitude block 2 accelerates since there are no other force acting on the body..

What surface? Which body? Please take the time to gather your thoughts and write a self-contained argument. We are not mind readers ... What is your free body diagram and what conclusions can you draw from it?

It is also unclear from your picture what a1 and a2 are the accelerations of and in which directions they go.

 

[Vv anand]

Let me stop you right there. Force and acceleration have different physical dinension. It makes no sense whatsoever to take a difference between a force and an acceleration.What surface? Which body? Please take the time to gather your thoughts and write a self-contained argument. We are not mind readers ... What is your free body diagram and what conclusions can you draw from it?

It is also unclear from your picture what a1 and a2 are the accelerations of and in which directions they go.

NVM leave it... I'll apply my mind or ask my teacher.
Thnx a lot for your precious time..

 

[Orodruin]

NVM leave it... I'll apply my mind or ask my teacher.
Thnx a lot for your precious time..

I think you might have a misconception of what this forum is for. Nobody here will spoon feed you answers. What we can do is to help you think in the right direction, but in order to do so you must be able to gather and present your thought process. You were always going to have to do dome thinking on your own, it is the only way to learn.

 

[Vv anand]

I

I think you might have a misconception of what this forum is for. Nobody here will spoon feed you answers. What we can do is to help you think in the right direction, but in order to do so you must be able to gather and present your thought process. You were always going to have to do dome thinking on your own, it is the only way to learn.

Got that soln myself sir... Just had a miscommunication which made me impatient

 

[Vv anand]

I

Got that soln myself sir... Just had a miscommunication which made me impatient

I already know what this forum is for and I know that i hv to be within those guidelines no matter what..."This is the way i will learn!"