Explaining Rotational Mechanics: Friction and Stationary Disc

AI Thread Summary
When a disc is placed on a plank and the plank is pulled, friction between the two creates an unbalanced torque, causing the disc to rotate. However, the discussion raises the question of why the disc appears stationary despite this friction, suggesting a misunderstanding of the mechanics involved. Participants express confusion about the assumptions regarding the disc's motion and reference Newton's laws to clarify the situation. Additionally, there is mention of a coaching institute that provides challenging questions related to this topic, indicating a focus on advanced understanding. Overall, the conversation revolves around the complexities of rotational mechanics and the effects of friction on motion.
AdityaDev
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When you put o disc on top of a plank and if you pull the plank, the disc rotates but stays stationary.
Here the friction between the plank and disk produces an unbalanced torque and hence it spins.But this friction should also cause an acceleration in the disc right? Then why does it remain stationary?
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who gived the assumption that it stay stationary? it does not stay stationary at all i think, just apply Newton's law...i'm curios about answers to this question :)
 
GiuseppeR7 said:
who gived the assumption that it stay stationary? it does not stay stationary at all i think, just apply Newton's law...i'm curios about answers to this question :)
Sorry. It doesn't stay stationary. Actually i was thinking about this question. I did not understand it properly.
I got the first two correct but i am still working on Q3.
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ah ok :) what book is that by the way? title and author? thanks!
 
GiuseppeR7 said:
ah ok :) what book is that by the way? title and author? thanks!
You can't buy it. You have to join my coaching institute. The questions are set by some reputed teachers and the book gets updated every year. No particular author. It's called Grand Masters Package.the questions are very difficult.
 
ah ok...thank you :)
 

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