Why does the Doppler shift vanish when source and detector move at the same speed?

[Ishu]

hi what will happen to the sign on doppler's general equation when both source and dectector are moving in the same direction at the same speed.? I didnt find this on my books.? Does anyone knows?

dopler equation

F' = f (V +/- Vd)
------------
(V +/- Vs)


?

 

[Ishu]

Does anybody know about this?

 

[mantito]

if both source and dectector are moving in the same direction at the same speed, is there a relative speed between them?

then, does it matter what the sign is?

 

[Ishu]

yeah both of them are at same direction at same speed 160 km

 

[Eivind]

There won't be any doppler effect when both the observer and source is moving at the same rate of speed.