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Does the Doppler Effect mean that an observer ahead of a train hears the train at a higher frequency sound than an observer behind the train?
Wiki User
∙ 7y ago
Yes that is the case.
Wiki User
∙ 7y ago
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How does the frequency measured in front of the source appear to the observer compared to the frequency measured from behind?
The frequencies are the same, unless the source is moving relative to the observer.
If light always travels at the same speed how can its color shift to red due to the Doppler effect?
As you mention light speed is constant. Light speed equals to its wavelength times its frequency. c = lambda * freq As the light source travels toward the observer, in such high speeds comparable to the light speed relative to the observer, the later emitted light waves pile up behind the earlier emitted light waves as they all travel together toward the observer, causing a visible shift (higher) in the frequency of the received waves as seen by the observer.
What is the sound or pitch when an ambulance goes by?
This is the doppler effect. If an ambulance is driving towards Jon, the sound waves are tightly stacked in front of the ambulance and are heard by Jon at a high frequency (high pitch). But behind the ambulance the sound waves are lagging because the ambulance is driving away from they sound waves (they are moving in the opposite direction) thus if Jon was standing behind the ambulance the frequency heard would be low (low pitch). The actual sound an ambulance makes is actually obnoxious, and if 100 of them drive by someone's apartment each day, it will make their head hurt and they will often think about why ambulances are so annoying.
What is the area behind the color violet called?
The next frequency, shorter than violet, is called ultraviolet, or UV for short.
What is the definition of gravitational?
Gravitational is a term used to refer adjectively to gravity, or to the actions associated with or resulting from the force of gravity. A good example is gravitational lensing, which refers to the effect that a massive gravity well has on light originating behind it and moving "around" it to reach an observer.
The velocity of sound in air is 343 ms An ambulance is traveling east at 64.9 ms Behind it there is a car traveling along the same direction at 29.8 ms The ambulance driver hears his siren at a?
afrequency of the same as siren frequency as ambulance is the source and the observer this is not Doppler effect problem
The Doppler effect says that if v0 is greater then vs then an observer will hear a higher pitch in front of source does that mean if vs is greater v0 an observer will hear a higher pitch BEHIND source?
Yes. vs > v0 and you're behind the source means you're catching up to it. Only the relative motion matters for the Doppler effect. Even though you're behind the source and it's moving away from you in absolute terms, you're moving toward it in relative terms.
How does the frequency measured in front of the source appear to the observer compared to the frequency measured from behind?
The frequencies are the same, unless the source is moving relative to the observer.
If light always travels at the same speed how can its color shift to red due to the Doppler effect?
As you mention light speed is constant. Light speed equals to its wavelength times its frequency. c = lambda * freq As the light source travels toward the observer, in such high speeds comparable to the light speed relative to the observer, the later emitted light waves pile up behind the earlier emitted light waves as they all travel together toward the observer, causing a visible shift (higher) in the frequency of the received waves as seen by the observer.
How to calculate apparent frequency the source is ahead and observer is behind both moving the same direction?
The apparent frequency does not depend on who is in front.
Describe the Doppler effect?
VROOOOOOOMMMM! The change in pitch when a car speeds by, first higher (when approaching) then lower (when receding).The Doppler effect is the term we give to the apparent change in frequency of waves (often light or sound waves) as the distance between the source and the observer changes. If either the source or the observer of a wave is moving so that the effect is that they are getting farther apart or closer together, the Doppler effect will appear. Let's look more closely.If the distance between the observer and the source of a wave is decreasing because they are closing in on each other, something happens. The wave, which is normally characterized by a given frequency and an associated wavelength, will appear to increase in frequency (and decrease in wavelength). Let's get even closer and break it down a bit to see what happens.When a wave reaches at an observer, it has a given wavelength. If there is no change in the distance between that observer and the source that wavelength remains constant. But if the distance of separation is decreasing (say if the sensor - observer - moves towards the source 8motion is relative so it does not matter which of the source or sensor moves relative to any frame of reference), as the crests and troughs of the wave arrive the observer will be (apparently) "running towards the next peak or trough" of the wave. This makes the wave appear to have a shorter wavelength. The observer is "running to intercept" the oncoming wave and the next crest or trough will "arrive sooner" because of the relative motion. This gives the effect of a change of frequency of the wave, and it makes it appear higher in frequency (with an accompanying shorter wavelength).If there is no change in distance between the source and the observer, the wave has a given wavelength. When a crest of the wave arrives at the observer's position, it takes "x" amount of time for the next crest to arrive. That's the period of the wave, or the time it takes for one complete cycle of the wave to occur. If the source and/or observer are/is moving relative to one another and the distance is closing, the "next crest" will "arrive sooner" and the period of the wave is effectively reduced. A shorter period of a wave equates to a higher frequency and a shorter wavelength. As the distance between the observer and the source opens, the opposite effect can be seen. Doppler effect isn't too tough to get a handle on if you work with it and think it through.If you've ever stood beside a roadway (or railroad track) with a vehicle (or train) coming toward you at speed, it has a given pitch (frequency). As it passes and moves away, the pitch (frequency) goes down. Simple and easy to observe. In astronomy, we note that the colors of stars in very distant galaxies are "wrong" as we observe them, but by "shifting the frequency" to increase it, they take on their "correct" colors. (*We know the "correct" colors due to the obvious pattern of spectral lines which the elements in a star have. The distant galaxies are moving away from us, and the light they emit is lower in frequency as we observe it than it would be if we were not moving apart. That light has been shifted toward the lower end of the optical spectrum, which is toward the red end. This is red shift, or the so-called redshift (one word) you hear about in astrophysics.Need a link for more information? Look below and you'll find some.When pitch rises as sound approackes then drops as the source passes by example: sirens
Sonic booms occur when?
The object in question exceeds the speed of sound. Due to the Doppler Effect, the object is literally leaving it's sound behind, causing a large low frequency boom as it passes
What is droppler effect?
The Doppler effect is the mix of red shift and blue shift. For example when your walking down the street and a car drives up from behind you and you don't see it but hear it your hearing the blue shift of the Doppler effect. also same scenario but the car has passed and driving away in front of you then your hearing the red shift of the Doppler effect. hope that helps I'm in 8th grade might wanna check but I'm pretty sure that's right well that's what we learned today anyway...:)
What is apparent change in pitch of a sound caused by the motion of the object making the sound?
this is the Doppler effect where sound waves are compressed in front of a moving object and exapnded behind it. Thus the pitch appears higher as an object approaches than when it receeds. At just below Mach 1, the sound wave is compressed to twice the frequency so the Doppler shift would be almost 2 octaves (factor of 4 between compresson and expansion) as the object passed.
Stars moving away from the earth show a red shift Why?
The star is moving away from us. Therefore, the Doppler effect must be considered. The Doppler effect is waves (in this case light) will be compressed in front of a moving object and stretched behind the object. This stretching creates a long wavelength. Red light has a long wavelength (the longest of visible light), so we call this stretching red shift.
What is the sound or pitch when an ambulance goes by?
This is the doppler effect. If an ambulance is driving towards Jon, the sound waves are tightly stacked in front of the ambulance and are heard by Jon at a high frequency (high pitch). But behind the ambulance the sound waves are lagging because the ambulance is driving away from they sound waves (they are moving in the opposite direction) thus if Jon was standing behind the ambulance the frequency heard would be low (low pitch). The actual sound an ambulance makes is actually obnoxious, and if 100 of them drive by someone's apartment each day, it will make their head hurt and they will often think about why ambulances are so annoying.
What is legal when towing a person on water skis or similar device behind a vessel?
being towed behind a PWC with an operator and an observer on board
