Max ω of circular hoop rotating around a peg and oscillation

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SUMMARY

The discussion focuses on calculating the maximum angular velocity (ω) of a circular hoop rotating around a peg, utilizing fundamental physics equations such as F=ma, τ = Iα, and L = Iω. The participant correctly identifies the role of centripetal force and the moment of inertia, applying the parallel axis theorem to derive the moment of inertia for the hoop as I = MR² + MR². The conversation emphasizes the importance of solving the first part of the problem (A) to facilitate understanding of the second part (B).

PREREQUISITES
  • Understanding of rotational dynamics, specifically τ = Iα and L = Iω.
  • Familiarity with centripetal force concepts in circular motion.
  • Knowledge of the parallel axis theorem for calculating moment of inertia.
  • Basic proficiency in applying Newton's second law (F=ma) in rotational contexts.
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  • Study the derivation and application of the parallel axis theorem in rotational dynamics.
  • Learn about the relationship between centripetal force and angular velocity in circular motion.
  • Explore rotational energy equations and their application in solving dynamics problems.
  • Investigate advanced topics in oscillatory motion related to rotating bodies.
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Physics students, educators, and anyone interested in understanding the dynamics of rotating systems, particularly in mechanics and oscillatory motion.

Phantoful
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Homework Statement


nGpQKiT.png


Homework Equations


F=ma
τ = Iα = rF
v=rω, a=rα
L = Iω
Center of Mass/Moment of intertia equations

The Attempt at a Solution

[/B]
So right now I've tried to model the force acting on the ring as it goes around the peg, but I think centripetal force is involved and I'm not sure how to use that in my equations of motion. A general idea I have is that rotational velocity should be highest when the hoop's center is at it's lowest possible point.

Say the peg is the z-axis coming in/out of the page, the moment of inertia of the hoop should be in relation to that axis. By the parallel axis theorem and the fact that a ring's moment of inertia is usually MR2, it would be I = MR2 + MR2. From this should I be using rotational energy equations or am I far off/should do something else?

For B I am completely lost but I'm pretty sure I might need to solve A first for it.
 

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Phantoful said:
A general idea I have
Good idea. Your intiuition is good, but: on the basis of what physics considerations ?
Phantoful said:
centripetal force is involved
On the mark again ! [edit] to avoid wrongfooting you: specifics for it may not be needed for the answer..)
Phantoful said:
am I far off/should do something else
and again ! SO: no and no. Just go ahead (and post if stuck...)

Phantoful said:
For B I am completely lost but I'm pretty sure I might need to solve A first for it.
My feeling this time is different: there is no need, but solving A first is a good strategy.
 
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