Propagation of Disturbances By a Moving Object
Consider an object moving at speed V :
Vt1
t3
t2
V t =0
t1
Suppose that the atmospheric speed of sound is a . The body emits sound
waves as it travels through the atmosphere and these wave propagate away
from the body at speed a in an isotropic manner. For example, consider a
stationary sound source (like a lecturer or a stereo speaker):
Sound waves at
time t
Sound wave emitted
at t = t2
R2
R1
a
a
⇒ R1 = at1
&
R2 = at2
Sound wave emitted
at t = t1