Rotational Velocity: Force, Torque, & Axis Motion

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SUMMARY

The discussion centers on the relationship between force, torque, and angular velocity in a system with a fixed green axis and a rotating arm. The arm rotates clockwise at angular velocity w1, while a blue ring rotates counterclockwise at w2, with w2 being less than w1. The participant asserts that the angular velocity w2' is frame-independent and questions the existence of torque affecting w2'. The conclusion emphasizes that w2' does not require torque for its change, challenging the notion that angular velocity is frame-specific.

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  • Understanding of angular velocity and its frame of reference
  • Knowledge of torque and its effects on rotational motion
  • Familiarity with rigid body dynamics
  • Basic principles of force application in rotational systems
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Physics students, mechanical engineers, and anyone interested in the dynamics of rotational motion and the interplay between force and torque in rigid body systems.

Del8
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Hi,

The green axis is fixed to the ground. An arm is turning clockwise at w1. The blue ring is turning at w2, with w2<w1. w1 and w2 are in labo frame reference. The ring is turning around itself counterclockwise at w2'=w2-w1, w2' is in arm frame reference. There is no friction.
http://imagizer.imageshack.us/v2/800x600q90/673/UPZdj7.png

I apply a force Fa on the arm with my hand. The axis of the ring receives Fb, for me w2' is constant because there is no torque on the ring. Is it correct ? If not where is the torque for change w2' ?
 
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Your idea that angular velocity of a rigid body is frame-specific is false. It is frame-independent and invariant. What you denote ##\omega_2'## is not angular velocity and it need not have any 'torque' related to it.
 

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