Conceptual torque problem with multiple sized pulleys

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SUMMARY

The discussion centers on a conceptual torque problem involving multiple sized pulleys and tensions T1 and T2. The student incorrectly concludes that T2 must exert greater force than T1 due to clockwise acceleration. However, the correct reasoning indicates that while T1 must be greater than T2 for mass m2 to accelerate downward, the torque generated by T2 must exceed that of T1 to achieve clockwise rotation of the disk. Understanding the relationship between torque and tension is crucial in resolving this conceptual misunderstanding.

PREREQUISITES
  • Understanding of basic physics concepts, particularly torque and tension.
  • Familiarity with free body diagrams and their application in analyzing forces.
  • Knowledge of Newton's laws of motion, especially in rotational dynamics.
  • Concept of mass and acceleration in relation to pulley systems.
NEXT STEPS
  • Study the principles of torque calculation in rotational systems.
  • Learn how to construct and analyze free body diagrams for complex pulley systems.
  • Explore the relationship between tension and acceleration in multi-mass systems.
  • Investigate the effects of pulley size on torque and tension dynamics.
USEFUL FOR

Students studying physics, particularly those focusing on mechanics and rotational dynamics, as well as educators seeking to clarify common misconceptions in torque and tension relationships.

crybllrd
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Homework Statement


This is a six part conceptual question that is not difficult. However, the last part I am struggling with.
What is wrong with the following student's reasoning:
"The clockwise torque is greater than the counterclockwise torque because the disk is accelerating clockwise. For this to happen, T2 must pull harder on the disk than T1."

Here's a pic I drew:

2h6eq74.jpg


The Attempt at a Solution



Well I know the first sentence is correct.
But I also thought the second one is too.
A free body diagram would show m1 accelerating up, and m2 down. Therefore tension in
T1>T2.
What am I missing here?

EDIT: m1=m2
 
Physics news on Phys.org
It is correct that T1 must be greater than T2 if m2 accelerates downward. The reasoning is wrong. To accelerate the disk clockwise, the torque of T2 has to be greater than the torque of T1. How is torque defined?

ehild
 

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