Can we write equations for strings in pulley systems?

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  • Thread starter Thread starter Kartik.
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    Forces Pulleys String
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Discussion Overview

The discussion revolves around the possibility of writing equations for strings in pulley systems, focusing on scenarios involving both massless and massive strings. Participants explore the implications of tension and acceleration in these systems.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant asserts that equations can be written for blocks on a fixed pulley by considering tension and weight, questioning if similar equations can be applied to the string itself.
  • Another participant expresses confusion regarding the specifics of the question, indicating that while they expect the answer to be affirmative, the lack of clarity makes it difficult to respond.
  • A suggestion is made to provide a specific example of a pulley system to facilitate the discussion on writing equations.
  • A participant notes that if the string has mass, the tension will vary, but Newton's laws can still be applied. They also mention that a massless string transmits forces at a constant tension, with no net force acting on it, while still accelerating with the object it supports.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the clarity of the initial question or the specifics of writing equations for strings in pulley systems, indicating that multiple views and uncertainties remain.

Contextual Notes

The discussion highlights the dependence on the definitions of massless versus massive strings and the implications for tension and force in the system, which remain unresolved.

Kartik.
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Ofcourse we can write the equations for blocks on a single fixed pulley taking the tension upwards and weight as downwards and then equating according to the acceleration. Can we write equations for the string (massless or with mass)?
 
Last edited:
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Equations for what, where?
I would expect that the answer is "yes", but the question is quite unclear (at least to me).
 
If someone can rig up a system of pullies, then we can write the equations for that system. Why don't you suggest an example?
 
Last edited:
If the string has mass, its tension will be variable (not constant), but you can still apply Newton's laws to it. If it has no mass, it just serves to transmit forces between objects with mass, at a constant tension. There cannot be any net force acting on it, although it would still accelerate along with the object it supports.
 

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