Physics Book - User contributions [en]

Doppler Effect

2017-11-29T04:49:40Z

Bsang3: /* References */

This topic covers the Doppler Effect.

==The Main Idea==
The Doppler Effect is the change of wavelength or frequency of a wave whenever its source is moving relative to the observer. A real life example of the Doppler Effect is when a vehicle, for example an ambulance, passes by the observer and when the ambulance approaches, the pitch increases but after the ambulance passes by the observer, the sound drastically recedes, as shown in this YouTube video: https://www.youtube.com/watch?v=a3RfULw7aAY.

==Explanation==
The increase in frequency and smaller wavelength is due to the source of the waves moving towards the observer as each successive wave crest is emitted closer to the observer from the previous wave.

The drastic reduce of pitch after the source moves past the observer is due to the movement of the waves as seen in the image example below.

[[File:Doppler Effect.JPG]]

The Doppler Effect is not only shown in sound waves as in the example of the ambulance and the image above. But also with other waves such as water waves and light waves.

==Formula==
General Formula
::<math>f = \left( \frac{c + v_\text{r}}{c + v_\text{s}} \right) f_0 \,</math>
where
::<math>f{0}</math> is the emitted frequency;
::<math>f</math> is the observed frequency;
::<math>c \;</math> is the velocity of waves in the medium;
::<math>v_\text{r} \,</math> is the velocity of the receiver relative to the medium; positive if the receiver is moving towards the source (and negative in the other direction);
::<math>v_\text{s} \,</math> is the velocity of the source relative to the medium; positive if the source is moving away from the receiver (and negative in the other direction).

==Examples==

A cop car drives at 45 m/s toward the scene of a crime, with its siren blaring at a frequency of 2500 Hz. At what frequency do people hear the siren as it approaches? At what frequency do they hear it as it passes? The speed of sound in the air is 343 m/s.

[[File:SolutionforBrian.jpg]]

==Connectedness==
#I was always interested in sound as I am from New York and I love New York City. Having heard all of this noise from car honking, I was initially curious as to why there's such a huge change when the car moves past me when I'm walking on the sidewalk. I've later watched The Big Bang Theory and they explained as to why this occurs so I was always fascinated by this topic.

==History==
Christian Doppler formulated the principle the Doppler Effect as he is an Austrian mathematician and physicist. The principle originated in his essay from 1842 "On the coloured light of the binary stars and some other stars of the heavens". He came across the Doppler Effect as he tried to come up with an explanation of the color of binary stars.

== See also ==

===Further reading===

Books, Articles or other print media on this topic
#http://www.physicsclassroom.com/class/waves/Lesson-3/The-Doppler-Effect

===External links===

Internet resources on this topic

#Sheldon's (From The Big Bang Theory) Explanation: https://www.youtube.com/watch?v=Y5KaeCZ_AaY

==References==

This section contains the the references you used while writing this page

http://www.physicsclassroom.com/class/waves/Lesson-3/The-Doppler-Effect

https://www.khanacademy.org/science/physics/mechanical-waves-and-sound/doppler-effect/v/doppler-effect-formula-for-observed-frequency

http://www.sparknotes.com/testprep/books/sat2/physics/chapter17section6.rhtml

https://www.historychannel.com.au/this-day-in-history/doppler-is-born-his-effect-soon-discovered/

[[Category:Which Category did you place this in?]]

Doppler Effect

2017-11-29T04:49:27Z

Bsang3: /* References */

This topic covers the Doppler Effect.

==The Main Idea==
The Doppler Effect is the change of wavelength or frequency of a wave whenever its source is moving relative to the observer. A real life example of the Doppler Effect is when a vehicle, for example an ambulance, passes by the observer and when the ambulance approaches, the pitch increases but after the ambulance passes by the observer, the sound drastically recedes, as shown in this YouTube video: https://www.youtube.com/watch?v=a3RfULw7aAY.

==Explanation==
The increase in frequency and smaller wavelength is due to the source of the waves moving towards the observer as each successive wave crest is emitted closer to the observer from the previous wave.

The drastic reduce of pitch after the source moves past the observer is due to the movement of the waves as seen in the image example below.

[[File:Doppler Effect.JPG]]

The Doppler Effect is not only shown in sound waves as in the example of the ambulance and the image above. But also with other waves such as water waves and light waves.

==Formula==
General Formula
::<math>f = \left( \frac{c + v_\text{r}}{c + v_\text{s}} \right) f_0 \,</math>
where
::<math>f{0}</math> is the emitted frequency;
::<math>f</math> is the observed frequency;
::<math>c \;</math> is the velocity of waves in the medium;
::<math>v_\text{r} \,</math> is the velocity of the receiver relative to the medium; positive if the receiver is moving towards the source (and negative in the other direction);
::<math>v_\text{s} \,</math> is the velocity of the source relative to the medium; positive if the source is moving away from the receiver (and negative in the other direction).

==Examples==

A cop car drives at 45 m/s toward the scene of a crime, with its siren blaring at a frequency of 2500 Hz. At what frequency do people hear the siren as it approaches? At what frequency do they hear it as it passes? The speed of sound in the air is 343 m/s.

[[File:SolutionforBrian.jpg]]

==Connectedness==
#I was always interested in sound as I am from New York and I love New York City. Having heard all of this noise from car honking, I was initially curious as to why there's such a huge change when the car moves past me when I'm walking on the sidewalk. I've later watched The Big Bang Theory and they explained as to why this occurs so I was always fascinated by this topic.

==History==
Christian Doppler formulated the principle the Doppler Effect as he is an Austrian mathematician and physicist. The principle originated in his essay from 1842 "On the coloured light of the binary stars and some other stars of the heavens". He came across the Doppler Effect as he tried to come up with an explanation of the color of binary stars.

== See also ==

===Further reading===

Books, Articles or other print media on this topic
#http://www.physicsclassroom.com/class/waves/Lesson-3/The-Doppler-Effect

===External links===

Internet resources on this topic

#Sheldon's (From The Big Bang Theory) Explanation: https://www.youtube.com/watch?v=Y5KaeCZ_AaY

==References==

This section contains the the references you used while writing this page

http://www.physicsclassroom.com/class/waves/Lesson-3/The-Doppler-Effect

https://www.khanacademy.org/science/physics/mechanical-waves-and-sound/doppler-effect/v/doppler-effect-formula-for-observed-frequency

http://www.school-for-champions.com/science/waves_doppler_effect_wavelength_derivations.htm#.Wh3WsEqnE2w

http://www.sparknotes.com/testprep/books/sat2/physics/chapter17section6.rhtml

https://www.historychannel.com.au/this-day-in-history/doppler-is-born-his-effect-soon-discovered/

[[Category:Which Category did you place this in?]]

Doppler Effect

2017-11-29T04:49:10Z

Bsang3: /* History */

This topic covers the Doppler Effect.

==The Main Idea==
The Doppler Effect is the change of wavelength or frequency of a wave whenever its source is moving relative to the observer. A real life example of the Doppler Effect is when a vehicle, for example an ambulance, passes by the observer and when the ambulance approaches, the pitch increases but after the ambulance passes by the observer, the sound drastically recedes, as shown in this YouTube video: https://www.youtube.com/watch?v=a3RfULw7aAY.

==Explanation==
The increase in frequency and smaller wavelength is due to the source of the waves moving towards the observer as each successive wave crest is emitted closer to the observer from the previous wave.

The drastic reduce of pitch after the source moves past the observer is due to the movement of the waves as seen in the image example below.

[[File:Doppler Effect.JPG]]

The Doppler Effect is not only shown in sound waves as in the example of the ambulance and the image above. But also with other waves such as water waves and light waves.

==Formula==
General Formula
::<math>f = \left( \frac{c + v_\text{r}}{c + v_\text{s}} \right) f_0 \,</math>
where
::<math>f{0}</math> is the emitted frequency;
::<math>f</math> is the observed frequency;
::<math>c \;</math> is the velocity of waves in the medium;
::<math>v_\text{r} \,</math> is the velocity of the receiver relative to the medium; positive if the receiver is moving towards the source (and negative in the other direction);
::<math>v_\text{s} \,</math> is the velocity of the source relative to the medium; positive if the source is moving away from the receiver (and negative in the other direction).

==Examples==

A cop car drives at 45 m/s toward the scene of a crime, with its siren blaring at a frequency of 2500 Hz. At what frequency do people hear the siren as it approaches? At what frequency do they hear it as it passes? The speed of sound in the air is 343 m/s.

[[File:SolutionforBrian.jpg]]

==Connectedness==
#I was always interested in sound as I am from New York and I love New York City. Having heard all of this noise from car honking, I was initially curious as to why there's such a huge change when the car moves past me when I'm walking on the sidewalk. I've later watched The Big Bang Theory and they explained as to why this occurs so I was always fascinated by this topic.

==History==
Christian Doppler formulated the principle the Doppler Effect as he is an Austrian mathematician and physicist. The principle originated in his essay from 1842 "On the coloured light of the binary stars and some other stars of the heavens". He came across the Doppler Effect as he tried to come up with an explanation of the color of binary stars.

== See also ==

===Further reading===

Books, Articles or other print media on this topic
#http://www.physicsclassroom.com/class/waves/Lesson-3/The-Doppler-Effect

===External links===

Internet resources on this topic

#Sheldon's (From The Big Bang Theory) Explanation: https://www.youtube.com/watch?v=Y5KaeCZ_AaY

==References==

This section contains the the references you used while writing this page

http://www.physicsclassroom.com/class/waves/Lesson-3/The-Doppler-Effect

https://www.khanacademy.org/science/physics/mechanical-waves-and-sound/doppler-effect/v/doppler-effect-formula-for-observed-frequency

http://www.school-for-champions.com/science/waves_doppler_effect_wavelength_derivations.htm#.Wh3WsEqnE2w

http://www.sparknotes.com/testprep/books/sat2/physics/chapter17section6.rhtml

[[Category:Which Category did you place this in?]]

Doppler Effect

2017-11-29T04:42:54Z

Bsang3: /* Connectedness */

This topic covers the Doppler Effect.

==The Main Idea==
The Doppler Effect is the change of wavelength or frequency of a wave whenever its source is moving relative to the observer. A real life example of the Doppler Effect is when a vehicle, for example an ambulance, passes by the observer and when the ambulance approaches, the pitch increases but after the ambulance passes by the observer, the sound drastically recedes, as shown in this YouTube video: https://www.youtube.com/watch?v=a3RfULw7aAY.

==Explanation==
The increase in frequency and smaller wavelength is due to the source of the waves moving towards the observer as each successive wave crest is emitted closer to the observer from the previous wave.

The drastic reduce of pitch after the source moves past the observer is due to the movement of the waves as seen in the image example below.

[[File:Doppler Effect.JPG]]

The Doppler Effect is not only shown in sound waves as in the example of the ambulance and the image above. But also with other waves such as water waves and light waves.

==Formula==
General Formula
::<math>f = \left( \frac{c + v_\text{r}}{c + v_\text{s}} \right) f_0 \,</math>
where
::<math>f{0}</math> is the emitted frequency;
::<math>f</math> is the observed frequency;
::<math>c \;</math> is the velocity of waves in the medium;
::<math>v_\text{r} \,</math> is the velocity of the receiver relative to the medium; positive if the receiver is moving towards the source (and negative in the other direction);
::<math>v_\text{s} \,</math> is the velocity of the source relative to the medium; positive if the source is moving away from the receiver (and negative in the other direction).

==Examples==

A cop car drives at 45 m/s toward the scene of a crime, with its siren blaring at a frequency of 2500 Hz. At what frequency do people hear the siren as it approaches? At what frequency do they hear it as it passes? The speed of sound in the air is 343 m/s.

[[File:SolutionforBrian.jpg]]

==Connectedness==
#I was always interested in sound as I am from New York and I love New York City. Having heard all of this noise from car honking, I was initially curious as to why there's such a huge change when the car moves past me when I'm walking on the sidewalk. I've later watched The Big Bang Theory and they explained as to why this occurs so I was always fascinated by this topic.

==History==

Put this idea in historical context. Give the reader the Who, What, When, Where, and Why.

== See also ==

===Further reading===

Books, Articles or other print media on this topic
#http://www.physicsclassroom.com/class/waves/Lesson-3/The-Doppler-Effect

===External links===

Internet resources on this topic

#Sheldon's (From The Big Bang Theory) Explanation: https://www.youtube.com/watch?v=Y5KaeCZ_AaY

==References==

This section contains the the references you used while writing this page

http://www.physicsclassroom.com/class/waves/Lesson-3/The-Doppler-Effect

https://www.khanacademy.org/science/physics/mechanical-waves-and-sound/doppler-effect/v/doppler-effect-formula-for-observed-frequency

http://www.school-for-champions.com/science/waves_doppler_effect_wavelength_derivations.htm#.Wh3WsEqnE2w

http://www.sparknotes.com/testprep/books/sat2/physics/chapter17section6.rhtml

[[Category:Which Category did you place this in?]]

File:SolutionforBrian.jpg

2017-11-29T04:40:26Z

Bsang3: Bsang3 uploaded a new version of "File:SolutionforBrian.jpg"

2017-11-29T04:01:40Z

Bsang3: /* Formula */

This topic covers the Doppler Effect.

==The Main Idea==
The Doppler Effect is the change of wavelength or frequency of a wave whenever its source is moving relative to the observer. A real life example of the Doppler Effect is when a vehicle, for example an ambulance, passes by the observer and when the ambulance approaches, the pitch increases but after the ambulance passes by the observer, the sound drastically recedes, as shown in this YouTube video: https://www.youtube.com/watch?v=a3RfULw7aAY.

==Explanation==
The increase in frequency and smaller wavelength is due to the source of the waves moving towards the observer as each successive wave crest is emitted closer to the observer from the previous wave.

The drastic reduce of pitch after the source moves past the observer is due to the movement of the waves as seen in the image example below.

[[File:Doppler Effect.JPG]]

The Doppler Effect is not only shown in sound waves as in the example of the ambulance and the image above. But also with other waves such as water waves and light waves.

==Formula==
::<math>f = \left( \frac{c + v_\text{r}}{c + v_\text{s}} \right) f_0 \,</math>
where
::<math>c \;</math> is the velocity of waves in the medium;
::<math>v_\text{r} \,</math> is the velocity of the receiver relative to the medium; positive if the receiver is moving towards the source (and negative in the other direction);
::<math>v_\text{s} \,</math> is the velocity of the source relative to the medium; positive if the source is moving away from the receiver (and negative in the other direction).

==Examples==

A cop car drives at 30 m/s toward the scene of a crime, with its siren blaring at a frequency of 2000 Hz. At what frequency do people hear the siren as it approaches? At what frequency do they hear it as it passes? The speed of sound in the air is 343 m/s.

==Connectedness==
#How is this topic connected to something that you are interested in?
#How is it connected to your major?
#Is there an interesting industrial application?

==History==

Put this idea in historical context. Give the reader the Who, What, When, Where, and Why.

== See also ==

Are there related topics or categories in this wiki resource for the curious reader to explore? How does this topic fit into that context?

===Further reading===

Books, Articles or other print media on this topic
#http://www.physicsclassroom.com/class/waves/Lesson-3/The-Doppler-Effect

===External links===

Internet resources on this topic

#Sheldon's (From The Big Bang Theory) Explanation: https://www.youtube.com/watch?v=Y5KaeCZ_AaY

==References==

This section contains the the references you used while writing this page

[[Category:Which Category did you place this in?]]

Doppler Effect

2017-11-29T04:00:57Z

Bsang3:

2017-11-28T21:37:29Z

Bsang3: /* External links */

Claimed and made by Erich Hoffstetter

This topic covers Gravitational Potential Energy.

==The Main Idea==

State, in your own words, the main idea for this topic
Electric Field of Capacitor

===A Mathematical Model===

What are the mathematical equations that allow us to model this topic. For example <math>{\frac{d\vec{p}}{dt}}_{system} = \vec{F}_{net}</math> where '''p''' is the momentum of the system and '''F''' is the net force from the surroundings.

===A Computational Model===

How do we visualize or predict using this topic. Consider embedding some vpython code here [https://trinket.io/glowscript/31d0f9ad9e Teach hands-on with GlowScript]

==Examples==

Be sure to show all steps in your solution and include diagrams whenever possible

===Simple===
===Middling===
===Difficult===

==Connectedness==
#How is this topic connected to something that you are interested in?
#How is it connected to your major?
#Is there an interesting industrial application?

==History==

Put this idea in historical context. Give the reader the Who, What, When, Where, and Why.

== See also ==

Are there related topics or categories in this wiki resource for the curious reader to explore? How does this topic fit into that context?

===Further reading===

Books, Articles or other print media on this topic

===External links===

Internet resources on this topic
Sheldon's(From The Big Bang Theory) Explanation: https://www.youtube.com/watch?v=Y5KaeCZ_AaY

==References==

This section contains the the references you used while writing this page

[[Category:Which Category did you place this in?]]