You do not observe a Doppler effect when you listen to the car radio when you travel in your car.Why?

Question

How to prove it using the Doppler effect formula?

Answer 1

Because you are IN the car and traveling with the source of sound. Someone outside the car hearing your radio as you drive by will experience Dopper effect though.

You only observe Doppler effect when the source of the wave is moving away or towards you.

Or are you asking why there is no Doppler effect as we move away or towards the radio tower? That's a more interesting question. I think the radio frequency travels so fast (speed of light) that car movement doesn't make much of a difference (its like we don't experience Doppler shift with our car's headlights. Light just travels way too fast)

Answer 2

f_dopp = f_o * (1 + v/c)

where f_dopp is the doppler shift, fo is the transmitted frequency, v is the relative velocity between the reciever and transmitter, and c is the speed of light. The doppler shift also depends on the carrier frequency of the transmitted signal.

Lets say your car is moving at 100 m/s, (224 mph very very fast!) away from the transmitter tower broadcasting around 100 MHz. The doppler shift at the reciever will be (1e8)*(-1e2)/(3e8) = -33 Hz. This is measurable, but you would never notice the difference because the radio's channel select filter usually has a bandwidth of about 400kHz. A 33 Hz shift will make it look like the radio is tuned of center by a very small abount. You won't hear any difference.

Answer 3

I think what he is talking about the doppler effect with the source of the signal, and if your car is moving then you are moving towards or away from the radio tower that is broadcasting the signal. I believe the reason you don't observe it is because you are moving so slowly relative to the radio waves.

f' = (c+v)/(c) x f

v (your car driving down the highway at 60 mph) is so small compared to c (about 670,000,000 mph) that there really isn't a noticeable difference in frequency.

Answer 4

It's a matter of speed. Compared to the speed of light (and radio waves) the speed of your car is insignificant. If you did experience the Doppler effect on your car radio you would probably not recognize it. You wouldn't experience the shift in sound wave frequency you might expect. A slight change in frequency of an AM station would simply cause you to drift off channel much as if you were passing behind a hill. For an FM station it would result in a slight increase or decrease in volume. In neither case would you experience the dramatic shift in sound frequency that you hear when a race car passes you at speed or a train blows its horn as it passes a crossing. The frequency shift, if it occurred would be in the radio waves themselves not in the sound waves emanating from the speaker.

Answer 5

You have some serious control issues, your being too literal in your reading of the bible, lighten up because if you believe that you can force someone into Gods light, then all your doing is turning them away from him, why would they want one who forces people into belief in him? If it was your wifes car, you had no right to do that because it is hers, she don't mess with your car does she? Repect for peoples property is part of marriage. God said to provide for his wife and family, not to dominated it, re-read your vows dude, don't think it says anything about controling every aspect of a marriage, down to the point you taken. I can guess why your not married to her anymore, she probably couldn't get free of you soon enough. I guess being in charge of the family meant that you decided if and when kids would be born into it, that all TV and radio, magazines and stuff had to be cleared by you first, huh? There is no way you can block all influences in a persons life, doubt you had much luck in your marriage either did you? Get a life dude, your gonna be very lonely until the day you meet your maker, and I bet he'll ask you the same question regarding your views.

Answer 6

Because you, the radio, and the air between you are all moving together. It takes radial movement of at least one of the three to cause doppler shift.

Answer 7

You do with the rf frequency that the station is transmitting on. But the audio in the carrier wave come from the rate and amount that the wave changes. That remains the same.

Answer 8

Because you and the car are traveling at the same speed.

Answer 9

b/c radio is not moving relative to you, and neither does air between you and radio.