00:01
Good day.
00:01
The topic is about doppler effect.
00:03
Doppler effect or doppler shift accounts for the change in the frequency as the result of the motion of the moving motion of the object or the source.
00:14
So we set where we solve for the frequency that is heard by the listener as v plus vl over v plus vs times fs.
00:23
Where fl is the frequency heard by the listener or the observer, fs is the frequency emitted by the sound source, v is the speed of sound in air, vl is the velocity of the listener, and vs is the velocity of the source.
00:37
So we note of the conventions for the signs of vl, vs, and depending on the motion.
00:44
So suppose we have a locomotive that is moving towards a passenger that is at rest or standing beside a track.
00:53
The locomotive is moving at the speed of 30 meters per second, and it is meeting a sound at a frequency of 2 ,000, kilohertz.
01:02
Taking the velocity of sound in air as 340 meters per second, we wish to find the frequency that is heard by the listener of the approaching locomotive and that the frequency that is still heard by the listener when the locomotive is receding away from it.
01:18
So let us start for a.
01:26
So we note that in this case, vl is equal to zero because the listener, which is the passenger standing beside the track is stationary or set at rest.
01:44
So that means vl zero...