How do you finish rearranging the Doppler shift formula

In summary, the conversation discusses the use of the Doppler shift formula and rearranging it to find the correct answer. The speaker mentions needing to divide the answer by two and asks for an explanation. Another person points out that the frequencies were inverted and the formula should be negative. However, the speaker still needs to divide the final answer by two to get the correct result. They are then asked to show their work.
  • #1
McWilliams
3
0

Homework Statement



i am using the Doppler shift formula Fs=F0(1/1+-(vsource/c) i can rearrange it to an extent but when i use it to find my answer i i need to divide it by two in order to do it, every time. I would just like to understand why this is, or if i am doing it completely wrong.


The Attempt at a Solution


((Fs/F0)-1)*V(sound)=Vsource
but if i turn it into 2Vsource it comes out that i will get the right answer when i divide it by two to get vsource, so please explain why there is a two there.

Please and thank you for your help.
 
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  • #2
McWilliams said:
((Fs/F0)-1)*V(sound)=Vsource
If I understand your symbols, I think you've got the ratio of the frequencies upside down.
 
  • #3
Yes, thank you, they were reversed, that created my formula to be positive instead of a negative end number, but i still need to divide Vsource by 2 in order to get the correct answer.
 
  • #4
McWilliams said:
Yes, thank you, they were reversed, that created my formula to be positive instead of a negative end number, but i still need to divide Vsource by 2 in order to get the correct answer.
Show your work, then.
 
  • #5


I would like to clarify that the Doppler shift formula is typically written as Fs = F0 * (1 +/- (vsource/c)). The 'c' in the formula represents the speed of light, not the speed of sound. Additionally, the '1' in the parentheses should be squared to represent the square root of the denominator. With these corrections, the formula should look like this: Fs = F0 * (1 +/- (vsource/c))^2.

Now, to address your question about the '2' in the formula, it is actually not necessary. In some cases, it may appear in the formula if you are using certain units (such as in the case of using kilometers per hour for velocity instead of meters per second). However, in most cases, the '2' should not be there.

To rearrange the formula, you can start by dividing both sides by F0: (Fs/F0) = (1 +/- (vsource/c))^2. Then, you can take the square root of both sides: sqrt(Fs/F0) = 1 +/- (vsource/c). Finally, you can subtract 1 from both sides and multiply by c to get the final formula: vsource = c * (sqrt(Fs/F0) - 1). This should give you the correct answer without needing to divide by 2.

In general, it's important to carefully check the units and variables in the formula to make sure they are consistent and accurate. I hope this explanation helps you understand the rearrangement of the Doppler shift formula.
 

FAQ: How do you finish rearranging the Doppler shift formula

1. How do I rearrange the Doppler shift formula?

The Doppler shift formula can be rearranged by solving for the desired variable using algebraic manipulations. For example, to solve for the velocity of a moving object, the formula can be rearranged as v = (f2 - f1) / ((f1 + f2) / 2) * c, where v is the velocity, f1 and f2 are the frequencies, and c is the speed of light.

2. What is the purpose of rearranging the Doppler shift formula?

Rearranging the Doppler shift formula allows us to solve for different variables and understand the relationship between them. This can be useful in various fields such as astronomy, meteorology, and medical imaging.

3. Can the Doppler shift formula be rearranged for different types of waves?

Yes, the Doppler shift formula can be rearranged for different types of waves such as sound waves, light waves, and radio waves. However, the formula may vary slightly depending on the type of wave and the properties of the medium through which it is traveling.

4. Are there any limitations to rearranging the Doppler shift formula?

While algebraic manipulation can be used to rearrange the Doppler shift formula, there may be limitations in certain scenarios. For example, the formula assumes that the source of the wave and the observer are in motion relative to each other, and that the wave is traveling through a uniform medium.

5. How can I check if I have correctly rearranged the Doppler shift formula?

You can check your rearranged formula by plugging in different values for the variables and ensuring that the equation holds true. Additionally, you can compare your rearranged formula to established versions of the Doppler shift formula to see if they are equivalent.

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