Wave Theory Questions & Answers

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The discussion focuses on the mathematical calculation of wave equations for strings fixed at one end and free at the other. It highlights that the wave equation for a string with one end tied to an immovable wall involves reflection, leading to specific conditions for amplitude and phase. A loose end must exhibit maximum amplitude during oscillation due to boundary conditions, which require the tangent at that point to be horizontal to avoid vertical force components. Additionally, applying a short impulse to a string fixed at both ends can initiate resonance, with the harmonic level determined by the string's physical properties and the nature of the impulse. Understanding these principles is crucial for analyzing wave behavior in strings.
pinsky
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Hello there.

Can someone pleas shed lite on some of these questions.

How does one mathematically calculate (wave equation of a string that has one end tied on a unmoveable wall. The second wave is after reflecting from the wall) the first wave is known to us (u0 omega and k)

u_0 \; Sin(\omega t - kx)=- u_0' \; Sin(\omega t + kx + \phi)

Conditions for a wave on a string which has a lose end. Why does that point has to always have a maximum amplitude when the string is oscillating?

When we apply a short impulse (force*time) on a string which is attached between two unmovable walls, does it always start to resonate? What determines the harmonic level of the resonation?


have a nice day
 
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pinsky said:
Hello there.
Conditions for a wave on a string which has a lose end. Why does that point has to always have a maximum amplitude when the string is oscillating?
Because of your boundary condition the tangent to the string at the loose end have to be horizontal otherwise you would have a vertical component of force owed to the string tension
 
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