Equation for the tension in the string

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    String Tension
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Homework Help Overview

The discussion revolves around a physics problem involving two masses connected by a string over a pulley, specifically focusing on the calculation of tension and the relationship between the masses. The original poster is trying to determine the value of a variable k, given certain conditions about the masses and acceleration.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to calculate the value of k based on the acceleration of mass A and the tension in the string. Some participants question the assumptions made regarding the direction of acceleration and the relative masses of A and B.

Discussion Status

Participants are exploring different assumptions about the direction of acceleration and its impact on the value of k. Guidance has been offered regarding the implications of mass relationships, and the original poster has acknowledged a misunderstanding in their initial approach.

Contextual Notes

There is a specific constraint that k must be greater than 3, which is central to the problem and affects the calculations being discussed.

Gughanath
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Two objects A and B hang down on either side of a smotth pulley, connected by an inextensible string. The masses of the objects are 3m and km respectivly. A accelerated at 2/5g when released. g=9.8N. What is the value of k.
I worked it out to be 1.29, by writing an equation for the tension in the string for both objects. But the the value of k is supposed to be greater than 3. :confused: Did I use the wrong method?
 
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What direction does A accelerate? You assumed down, and got the correct answer for that assumption. If km > 3m, then A would accelerate up. Try making that assumption and solve for k.
 
yes. This time round I get k=7? Is this right?
 
Oh right. I didnt read the question properly. if k is bigger than 3, then obviously its the greater mass. Thanks for clearing my problem.
 

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