Brief explantation as to why x(max)= v(max)/ang freq?

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Homework Help Overview

The discussion revolves around understanding the relationship between maximum displacement and maximum velocity in the context of Simple Harmonic Motion (SHM). The original poster, Shawn, seeks clarification on why the equation \( x_{\text{max}} = \frac{v_{\text{max}}}{\omega} \) holds true, expressing confusion despite having solved a related homework problem.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss relevant equations from SHM, including the relationships between displacement, velocity, and angular frequency. Shawn shares specific values from a homework problem and expresses a desire to understand the underlying principles rather than just the calculations.

Discussion Status

Some participants have offered insights into the mathematical relationships involved, while others suggest that visualizing sine and cosine functions may aid in understanding the concepts. There is an exploration of how changes in amplitude and frequency affect velocity, but no consensus has been reached regarding a clear explanation of the original question.

Contextual Notes

Shawn notes that the confusion may stem from missed explanations in lectures or previous chapters, indicating a potential gap in foundational understanding. The discussion is framed within the constraints of homework rules, focusing on conceptual clarity rather than direct solutions.

Shawn Huetter
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I don't need help with my homework problem as I figured out the answers. But I'm still really confused on why it happened to work. I might be over thinking something that is soo simple but I've read over my chapter a few time on Simple Harmonic Motion and can't seem to find an explanation. So I come to you all to seek knowledge.
As the title states, why is it that the max displacement is equal to the max velocity over the angular frequency?

Thank you all kindly for any and all help,

Shawn
 
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Hello Shawn, :welcome:

You should really quote some relevant equations from your chapter, because now I have no idea if I can use the derivative of a sine to show you, or if I have to resort to more elementary ways to demonstrate this...
Can you follow the wiki lemma ?
 
Ok so I know that x(t)=xmaxcos(ωt+Φ), that v(t)=-ωxmaxsin(ωt+Φ), and that ω=2π/T or 2πf or √(k/m). *(Note: xmax is also known as A, for amplitude.)
My specific homework problem ask me to find the angular frequency and the max displacement give the mass of particle, period of oscillation, and the velocitymax.
Ill just go ahead and post those values even though I don't need the answer, I just want to understand why xdisplacement=velocitymax/ω.
Values:
Mass= 4.6E-20
T=3.7E-5
vmax=4.4E3

I worked out ω=(2π/3.7E-5) ⇒ 1.7E5 rad/s
And
xmax=(4.4E3/1.7E5) ⇒ 0.026m.
I'm just having trouble understanding why that work (for xmax).
It might be something simple I missed during my lecture or something that is from a previous chapter I might have overlook or missed, but I can't seem to find an explanation in my current chapter.

Hope this helps you understand my question to better explain to me.

Thank you,

Shawn
 
Sine and cosine have maximum absolute value 1, so all that's left is a factor ##\omega##. There isn't much more to explain about it.

Unless you count: v has to do with the rate of change of x: ##\ v = {\Delta x \over \Delta t}\ ## (in the limit ##\ \Delta t\downarrow 0##), so the faster x oscillates, the bigger v .

Another thing you can do is make a few drawings of sine waves: at x = 0 the rate of change in x (a.k.a. v) is maximum. Convince yourself that for a double amplitude in x, v doubles, and for the same amplitude but a double frequency, v doubles too.

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