Why Are There Different Formulas for Wave Velocity?

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There are two formulas for wave velocity: v=λ/T, which is a general equation applicable to all wave types, and V=√(T/μ), specific to transverse waves on a string. The first formula relates wavelength and time period, while the second incorporates tension and linear mass density. Both equations are correct but serve different contexts; the first is a broad definition, while the second applies to specific conditions. Understanding this distinction helps clarify how wave velocity can be represented in various scenarios. Ultimately, both formulas are valid, with one being a general principle and the other a specific application.
mooncrater
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Homework Statement


Actually its not a homework problem sort of thing...I was wandering through a book , studying waves then I realized that there were two formula for the same thing ...the velocity of a wave.

Homework Equations


v=λ/T [where λ is the wavelength and T is the time period]
V=√(T/μ) [where T is tension and μ is linear mass density]

The Attempt at a Solution


I don't know...are both of these correct and I am relating two different things ? or both of them are applied at different places ... I just don't get it...help needed...[/B]

Edit: Is it like that velocity of a wave is defined by the second formula and the first formula is just a relation between λ and T where v is a constant .[ Just like in the case of resistance in dc circuits where R=ρl/A actually defines Resistance whereas V=RI is just a realtion between V & I where R is just a constant]
 
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Your first expression is general and does not depend on the type of wave. It is derived essentially from basic wave motion and from how we define the wavelength and period.

The second expression is the speed of a transversal wave on a string. Using both expressions, you could essentially derive a relationship between the period and the wavelength in terms of the tension and the linear mass density for this type of wave.
 
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Okay i got it now. Both of them are correct...It is just that first one is general whereas 2nd one is for the particular case of a transversal wave.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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