What's the Dopler Effect?

Question

maybe its "affect" and plus, I'm not sure if I even spelled "dopler" right- any ideas?

Answer 1

Looks right to me. anyway here comes the sci. explaination.. bear with me for an example.

Waves move in any direction at a fixed speed and eventually slow down when acted on by external forces.

A largewave from Japan moves virtually unseen and at a constant speed all the way to the west coast of the US and then will dissipate by dragging on the bottom or slamming into a wall. But untill that happens its speed is constant

But what would happen if you could change the speed of the wave ?

Sound is a wave too.. you honk a horn and someone hears it down the street. The sound traveled there at a constant speed and arrived a few seconds later.

Now lets put that horn in a car and step on the gas.

Now lean on the horn while you are coming down the street at 100 mph. Start counting at 1000 feet.

The sound that left the horn at the 1000 foot mark will journey to your ear and take x seconds to get there. BUT within a few moments the next 'piece' of sound, will travel a shorter distance because the car has moved closer. So you are going to get a bit of overlap on the sound as it hits your ear. Likewise the next 'bit' of sound is going to overlap the first two and so on. This as the result of continuously changing the frequency of the sound and as a result the scale of the horn's note.

What you hear is the same sound as a railroad train passing by with its horn going.... The tone of the horn changes in your ear, but you know that the sound coming out of the train's horn must have been the same the whole time - right?

Presto.. THAT is the doppler effect (I think it DOES have 2 p's)

ok??

.

Answer 2

The Doppler effect, named after Christian Doppler, is the change in frequency and wavelength of a wave as perceived by an observer moving relative to the source of the waves. For waves that propagate in a wave medium, such as sound waves, the velocity of the observer and of the source are reckoned relative to the medium in which the waves are transmitted. The total Doppler effect may therefore result from either motion of the source or motion of the observer. Each of these effects is analyzed separately. For waves which do not require a medium, such as light or gravity in special relativity, only the relative difference in velocity between the observer and the source needs to be considered

Answer 3

doppler effect: when something is moving it will sound different to you then when it's standing still, that's why a train whistle sounds different when the train is moving towards you then when it's moving away.