Solving for Vv= The doppler Effect

AI Thread Summary
The discussion centers on solving for Vw in the context of the Doppler effect using a specific formula. The initial attempts to manipulate the equation lead to confusion, particularly with terms canceling out incorrectly. Participants clarify that the second step in the calculations is flawed and emphasize the importance of correctly isolating Vw. The correct approach involves rearranging the equation to collect terms with Vw on one side. Ultimately, the discussion aims to guide the user towards successfully isolating Vw for the Doppler effect problem.
XxphysicsxX
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The problem:
I have to answer a question about the Doppler effect using the formula attached.
I know i have to solve for Vw, but I get
Vw/Vw=(Fd/Fs)(-Fs)

and I am possitive that's not right, can someone please help me out??
Thankyou
 

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Transfer the denominator in the right hand side to the left hand side. Simplify and collect the terms containing fw.
 
i get:

Fd (Vw- Vs) = VwFs
Fd( Vw-Vs) - Vw= Fs

but the two Vw just cancel each other out again..
I don't know what I am doing wrong...
 
XxphysicsxX said:
i get:

Fd (Vw- Vs) = VwFs
Fd( Vw-Vs) - Vw= Fs
but the two Vw just cancel each other out again..
I don't know what I am doing wrong...

The second step is wrong.

Fd(Vw - Vs) = VwFs

FdVw - FdVs = VwFs
In the multiplication you cannot transfer a single term to the other side.
Now collect the terms containing vw on one side and find its expression.
 
XxphysicsxX said:
The problem:
I have to answer a question about the Doppler effect using the formula attached.
I know i have to solve for Vw, but I get
Vw/Vw=(Fd/Fs)(-Fs)

and I am positive that's not right, can someone please help me out??
Thankyou

Given Fd = [Vw/(Vw-Vs)]Fs then
(Vw-Vs)/Vw = Fs/Fd

Simplify the lefthand term to get Vw by itself and continue.
 

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