doppler formula help please!:)

chiuda

Hello, i see the doppler formula in 2 different forms one being f1=f2 (Vw/Vw-Vs) and the other f1=f2/(1+Vs/Vw)

f1= Doppler frequency
f2= Source frequency
Vw= Speed of sound
Vs= Speed of source

the problem i am having is understanding how these are equivalent? how fit they get from one to the other? And how would you solve for Vs in the first doppler equation stated? any help would be greatly appreciated :)

tiny-tim

hello chiuda!

if you replace Vs by -Vs, they're the same!

chiuda

yes i understand that part but lets say the 2nd eqn was already -vs how does one get from the first equation to the second one? it would be very appreciated if all the steps could be shown thank you :)

Norfonz

Try dividing up and bottom by Vw.

chiuda

then i would have f2*(1-Vs/Vw) which is not the same as f2/ (1-Vs/Vw) :S

tiny-tim

how do you get that?