1. Nov 6, 2008

atmostudent

1. Whenever we talk about a single frequency characterizing an electromagnetic wave, we are tacitly assuming that the source and the detector are stationary relative to one another. However, if the distance between the two is changing in velocity, V, then the frequency of radiation, ν1 emitted by the source will be different than the frequency ν2 observed by the detector. In particular, the frequency shift ∆ν = ν1 - ν2 is approximately proportional to the velocity, a phenomenon known as Doppler shift.
A.) Derive the precise relationship between ∆ν and velocity V, by considering the time lapse, ∆t, between two successive waves crests reaching the detector with speed c.

B.) For the case that V << c, show that your solution to 3A simplifies to a proportionality between ∆ν and V.

I was thinking for A.) maybe something along the lines of

V(∆t) = ∆ν/c

using V = v * wavelenght and

wavelength = c/v