Formula for maximum angular frequency and velocity

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Discussion Overview

The discussion revolves around the formulas for maximum angular frequency and velocity in the context of pendulum motion. Participants explore the meanings and implications of the equations Vmax=Wmax x L and Wmax=Wθmax, with a focus on their application to pendulum dynamics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant seeks clarification on the formula Vmax=Wmax x L, suggesting it represents the maximum speed of the pendulum bob as Vmax=ωmaxL, where ωmax is the maximum angular speed and L is the string length.
  • Another participant expresses uncertainty about the meaning of Wmax=Wθmax, noting the potential confusion due to the use of two different notations for angular frequency.
  • A participant proposes that ωmax represents the rotation rate of the pendulum at the bottom of its swing, while ω refers to the angular frequency of the oscillations, and θmax is the maximum deflection angle from the vertical.
  • One participant suggests an alternative expression for ωmax, proposing it should be ωmax=θmax√(g/L), emphasizing the distinction between angular speed and angular frequency.

Areas of Agreement / Disagreement

Participants express varying interpretations of the formulas and their components, indicating that multiple competing views remain regarding the correct understanding and application of the equations.

Contextual Notes

The discussion highlights potential confusion arising from the notation used in the formulas, as well as the assumptions related to the definitions of angular frequency and angular speed in the context of pendulum motion.

MenchiKatsu
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I can't seem to find it anywhere
What does this formula mean ? I can't find it anywhere. Vmax=Wmax x L. And Wmax=Wθmax. It came up in the pendulum chapter. L is string length.
 
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I can imagine that Vmax=Wmax x L is actually ##V_{\text{max}}=\omega_{\text{max}}L## where
##V_{\text{max}}=~## maximum speed of the pendulum bob
##\omega_{\text{max}}=~## maximum angular speed of the pendulum relative to the point of support
##L=~## the length of the pendulum.

I cannot imagine what Wmax=Wθmax could be.
 
MenchiKatsu said:
And Wmax=Wθmax. It came up in the pendulum chapter. L is string length.
$$\omega_\text{max} = \omega \theta_\text{max}$$I will make a guess at this one. The notation is confusing because there are two different omegas (##\omega##) being considered here.

On the left hand side of the equality we have ##\omega_\text{max}## which is the rotation rate (in radians per unit of time) for the pendulum at the bottom of its swing.

On the right hand side of the equality we have ##\omega## which is the angular frequency of the oscillations of the pendulum.

Finally we have ##\theta_\text{max}## which is the maximum deflection angle of the pendulum from the vertical.

For instance...

If we have a one meter pendulum under earth gravity, its period is about two seconds. This is an angular frequency (##\omega##) of about ##2 \pi## radians per ##2## seconds. Or about one radian per second.

If this pendulum is launched from rest at a deflection angle (##\theta_\text{max}##) of ##0.1## radians from the vertical, the equation asserts that the rotation rate (##\omega_\text{max}##) of the pendulum at the bottom of its arc will be ##0.1## radians per second.
 
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jbriggs444 said:
I will make a guess at this one. The notation is confusing because there are two different omegas (ω) being considered here.
I agree. It should be something like $$\omega_{\text{max}}=\theta_{\text{max}}\sqrt{\frac{g}{L}}$$ where ##\omega## is a reserved symbol for the angular speed of the pendulum bob.
 
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