High School What is physical significance of the direction of angular velocity?

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SUMMARY

The direction of angular velocity and torque is defined by the right-hand thumb rule, indicating that it is perpendicular to the rotational plane. This direction signifies the orientation of the rotational plane or axis, serving as a normal or parallel vector. While the choice of convention may appear arbitrary, it becomes crucial in complex scenarios, such as when an applied moment induces opposite rotational acceleration or when estimating combined directions of angular velocity and torque in multi-axis rotations. Understanding these concepts is essential for analyzing rotational dynamics effectively.

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  • Understanding of angular velocity and torque concepts
  • Familiarity with the right-hand thumb rule
  • Basic knowledge of rotational dynamics
  • Experience with vector analysis in physics
NEXT STEPS
  • Research the implications of the right-hand rule in advanced rotational dynamics
  • Study the effects of applied moments on angular acceleration
  • Explore multi-axis rotation scenarios in physics
  • Learn about angular momentum and its relationship with torque
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Physics students, mechanical engineers, and anyone interested in understanding the principles of rotational dynamics and vector analysis in motion.

mdcreator
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This question has been bugging me for quite a while, That what do we mean by direction of angular velocity or torque. As we know that the direction of angular velocity or torque even is determined by right hand thumb rule, and it come out to be perpendicular to the rotational plane. So my question is what does this direction signify? Specifically what does it signify physically?
 
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mdcreator said:
... it come out to be perpendicular to the rotational plane. So my question is what does this direction signify?
You have just answered your own question: It describes the orientation of the rotational plane (as its normal) or of the rotational axis (as its parallel).

However, this still gives you two possible vector orientations which represent two rotation directions in that plane. The correspondence here is an arbitrary convention, and has no physical reason. We could have just as well agreed to using the left hand rule.
 
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Welcome, @mdcreator !

At first glance, the convention may seem to be useless for rotational velocity and torque of a disc, but it helps when things get more complicated.

Examples:
In cases where applied moment induces a opposite rotational acceleration that is retarding the angular velocity.

Estimating the combined direction of angular velocity or torque of the above rotating disc which begins to simultaneously rotate about another axis and at a different rate.

Estimating the combined direction of changes of angular acceleration and angular momentum.

Please, see:
https://courses.lumenlearning.com/suny-osuniversityphysics/chapter/10-1-rotational-variables/

CNX_UPhysics_10_01_AngAccVec.jpg
 
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