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Why do you hear a higher pitched sound when an ambulance is moving toward you and a lower sound when an ambulance is moving away from you than you would if you and the ambulance were both at rest?
Wiki User
∙ 10y ago
That's called the "Doppler" effect, named for the scientist who explained it.
You're standing still, but the train or ambulance is moving toward you. The horn or siren is going. The sound waves go out in every direction, at the speed of sound (about 750 miles per hour, depending on atmospheric pressure).
As the train is moving TOWARD you, the sound waves that it generates are being pushed together, because the train is moving too. We hear the effect as if the frequency of the sound waves is pushed together, increasing the frequency. As the train passes by, we hear the "Doppler shift" to the lower frequency, because how the train is moving AWAY and the sound frequencies are stretched out. Now we hear the sound at a lower frequency.
If we carefully analyze the Doppler shift, we can determine;
1. Exactly how fast the train was moving
2. How far away the train was when it passed by.
Police use the same thing; you're driving along the highway, and a police officer points his radar gun at your car. The radar gun is precisely calibrated for frequency. The radar waves hit your car and bounce off, and the Doppler-shifted frequency can be used to calculate how fast you were going.
Wiki User
∙ 10y ago
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The ambulance is moving toward you and your sound technology measures the pitch at 645 hertz. The speed of the ambulance is therefore ______ m/s.?
*this is the full question not the answer* Suppose you’re standing on a sidewalk and down the street is an ambulance parked; it’s siren is a 600 Hz sound like it louder, Quieter, louder, quieter, etc. By now, you should understand that if the ambulance drivers toward you the pitch will be higher than 600 Hz. BUT HOW MUCH HIGHER? The amount is directly proportional to speed!(this means waves can be used as a speedometer!) here’s a fact: if the ambulance approached you at 8.5 m/s, the pitch would raise by 15 Hz: you would here 615 Hz instead of 600. But if the ambulance came at you twice as fast— 8.5+8.5=17.0 m/s — The pitch would raise by 30 Hz, you were here at 630 Hz sound. Question: do use the facts given above to answer this:The ambulance is moving toward you and your sound technology measures the pitch at 645 hertz. The speed of the ambulance is therefore ______ m/s.
Objects that are moving away from us give off what light and objects that aremoving toward us gives what light?
Due to the doppler effect, objects moving toward us will be slightly more red than what they actually are, and objects moving away will be slightly more blue. Think of it like a siren coming toward you and moving away from you. If it is moving toward you, it will be slightly higher than what it really sounds like. If it is moving away it will have a slightly lower pitch.
What lets you know that the source of a sound is moving toward or away from you?
When a sound-source moves toward you, its pitch gets higher and the sound gets louder. When it moves away, the pitch lowers and it gets quieter. The frequency change is called the Doppler shift.
What is the society which some forecasters say that the world is moving toward?
We are moving toward a cashless society.
What happens if the source of a sound is toward you at a high rate of speed?
If the source of a sound is moving towards you, then the pitch of the soundyou hear is higher than the pitch of sound that the source is actually emitting.The rate of speed doesn't matter.BTW ... this also happens if you are moving toward the source.
Why the particle is not moving toward negative x-direction?
Why the partical is not moving toward negative x-direction?
How can astronomers determine whether star is moving toward or away from earth?
Astronomers determine whether a star is moving toward or away from the Earth via the Doppler effect. Imagine a motorcycle moving past you. As it drives towards you, it has a higher frequency, and a lower frequency when it drives away. The same thing happens with light. As an object moves towards us, its light has a higher frequency and lower wavelength - this is called blueshift. As an object moves away from us, its light has a lower frequency and higher wavelength - this is called redshift.
If something is being carried by westerlieswhat direction is it moving toward?
It is moving toward the east. westerly describes the direction the wind comes from
Which has a higher frequency a star moving away from earth or towards earth?
I would think that current evidence suggests that the stars moving away from earth, some of them in far distant galaxies moving at unimaginably high speeds, are going much faster than stars moving toward us. The entire Andromeda galaxy is moving toward us and will collide with us in roughly 5 billion years, and it is not moving anywhere near as fast as the distant retreating galaxies.
What rhymes with moving forward?
Going toward
Why can't the earth be seen moving toward you when you jump up in the air?
you can't see it moving because your moving with it
In what direction is California moving?
California is slowly moving south, toward the Gulf of Mexico.
