Question

I want someone explain to me (the doppler effect) also i need the formula for each case or situation please ..

Thank you .. ??

Answer 1

Doppler Effect: Doppler Effect refers to the change in wave frequency during the relative motion between a wave source and its observer. or

apparent change in the frequency of a wave motion when there is relative motion between the source and the observer.

v = speed of sound, v_O = speed of observer

Case I: When observer moving and source stationary;

(a) observer moving towards source

apparent frequency f' = f(v + v_o)/ v;

(b) observer moving away from source

apparent frequency f' = f(v - v_o)/ v;

Case II: When source moving and observer stationary;

(a) source moving towards observer

apparent frequency f' = fv/ (v - v_s);

(b) source moving away from observer

apparent frequency f' = fv/ (v + v_s).

Generalized form for all the cases>

apparent frequency

Switch appropriate signs if observer or source moves away.