Difference between revisions of "Apps-On-Physics/C2/Sound-waves/English"

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Line 7: Line 7:
  
 
'''Title Slide '''
 
'''Title Slide '''
−
|| Welcome to the Spoken Tutorial on '''Sound waves.'''
+
|| Welcome to the spoken tutorial on '''Sound Waves'''.
 
|-
 
|-
 
|| '''Slide Number 2 '''
 
|| '''Slide Number 2 '''
  
−
'''Learning Goals'''
+
'''Learning Objectives'''
−
|| In this tutorial we will demonstrate,
+
|| In this tutorial we will,
 +
 
 +
Form a standing wave.
 +
 
 +
Form nodes and antinodes.
 +
 
 +
View various types of harmonics of a standing wave.
 +
 
 +
Calculate the wavelength and frequency of standing waves.
  
−
'''Standing Wave''' and '''Standing Longitudinal Waves Apps'''.
 
  
 
|-
 
|-
Line 22: Line 29:
 
|| Here I am using,
 
|| Here I am using,
  
−
Ubuntu Linux OS version 16.04
+
* '''Ubuntu Linux''' OS version 16.04
−
 
+
* '''Firefox web browser''' version 62.0.3
−
Firefox web browser version 62.0.3
+
|-  
−
|-
+
 
|| '''Slide Number 4'''
 
|| '''Slide Number 4'''
−
 
+
'''Pre-requitsites'''  
−
'''Pre-requities'''
+
  
 
'''https://spoken-tutorial.org'''
 
'''https://spoken-tutorial.org'''
Line 34: Line 39:
  
 
For the pre-requisite tutorials please visit this site.
 
For the pre-requisite tutorials please visit this site.
 +
 
|-
 
|-
 
|| '''Slide Number 5'''
 
|| '''Slide Number 5'''
  
 
'''Learning Goals'''
 
'''Learning Goals'''
−
|| Using these''' Apps''' we will,
+
||Calculate the wavelength and frequency of standing waves.
−
* Demonstrate the formation of a standing wave.
+
−
* Explain the formation of '''nodes''' and '''antinodes'''.
+
−
* Demonstrate harmonics of a standing wave.
+
−
 
+
 
|-
 
|-
 
|| '''Slide Number 6'''
 
|| '''Slide Number 6'''
  
−
'''Learning Goals'''
+
Link for '''Apps on physics'''
−
||Calculate the wavelength and frequency of standing waves.
+
  
 +
'''https://www.walter-fendt.de/html5/phen/'''
 +
|| Use the given link to download the '''Apps'''.
  
 +
|-
 +
|| Point to the file in the''' Downloads''' folder
 +
|| I have downloaded the '''Apps''' to my '''Downloads''' folder.
  
 
|-
 
|-
−
|| '''Slide Number 9'''
+
||'''Slide Number 7'''
  
−
Link for Apps on physics
+
'''Apps on Physics'''
 +
||In this tutorial we will use,
  
−
'''https://www.walter-fendt.de/html5/phen/'''
+
'''Standing Wave''' and '''Standing Longitudinal Waves Apps'''.
−
|| Use the given link to download the '''Apps'''.
+
  
 
|-
 
|-
−
|| Point to the file in the''' Downloads''' folder
+
|| Right-click on '''standingwavereflection_en.htm''' file.
−
|| I have downloaded the '''Apps '''to my '''Downloads''' folder.
+
−
|-
+
−
|| Right click on '''standingwavereflection_en.htm''' file.
+
  
 
Select option '''Open With Firefox Web Browser '''option.
 
Select option '''Open With Firefox Web Browser '''option.
−
|| Right click on''' standingwavereflection_en.htm '''file.
+
|| Right-click on '''standingwavereflection_en.htm''' file.
  
−
Select the option '''Open With''' '''Firefox Web Browser'''.
+
Select the option '''Open with Firefox Web Browser'''.
  
−
'''Standing wave App '''opens in the browser.
+
'''Standing Wave App''' opens in the '''browser'''.
 
|-
 
|-
 
|| Point to the radio buttons,
 
|| Point to the radio buttons,
  
 
'''Reflection from a fixed end '''and '''Reflection from a free end'''.
 
'''Reflection from a fixed end '''and '''Reflection from a free end'''.
−
|| In the green panel under '''Reflection''' we have  
+
|| In the green panel under '''Reflection''' we have two radio buttons.
  
−
two radio buttons.
+
* '''from a fixed end ''' and  
−
 
+
* '''from a free end'''.
−
'''from a fixed end '''and '''from a free end'''.
+
 
|-
 
|-
 
|| Point to '''Reflection from a fixed end.'''
 
|| Point to '''Reflection from a fixed end.'''
Line 88: Line 90:
 
|-
 
|-
 
|| Point to '''Start '''>>''' Pause''' >> '''Resume.'''
 
|| Point to '''Start '''>>''' Pause''' >> '''Resume.'''
−
|| '''Start '''button is a toggle for '''Start'''/ '''Pause''' and '''Resume'''.
+
|| '''Start '''button is a toggle for '''Start, Pause''' and '''Resume'''.
 
|-
 
|-
 
|| Point to the three check-boxes
 
|| Point to the three check-boxes
  
−
'''ncidenting wave'''
+
'''Incidenting wave'''
  
 
'''Reflected wave '''and
 
'''Reflected wave '''and
Line 99: Line 101:
 
|| At the bottom of the green panel you can see  
 
|| At the bottom of the green panel you can see  
  
−
'''Incidenting wave'''
+
* '''Incidenting wave'''
−
 
+
* '''Reflected wave '''and
−
'''Reflected wave '''and
+
* '''Resultant standing wave''' check-boxes.
−
 
+
−
'''Resultant standing wave''' check-boxes.
+
 
|-
 
|-
 
|| Point to the check-boxes.
 
|| Point to the check-boxes.
Line 142: Line 142:
 
|-
 
|-
 
|| Point to the resultant wave.
 
|| Point to the resultant wave.
−
|| Here is the resultant standing wave.
+
|| Here is the resultant '''standing wave'''.
 
|-
 
|-
−
||  
+
|| Pause the '''App''' when it shows this image.
−
 
+
−
Pause the '''App''' when it shows this image.
+
−
 
+
 
|| This wave is formed due to the superposition of incident and reflected waves.
 
|| This wave is formed due to the superposition of incident and reflected waves.
  
Line 165: Line 162:
  
 
Point to '''T/8.'''
 
Point to '''T/8.'''
−
|| Below the '''Single steps''' radio button, a drop down to show various time periods is seen.
+
|| Here a drop down to show various time periods is seen.
  
  
−
By default it is '''T/8'''.
+
By default it is '''T by 8'''.
  
  
Line 176: Line 173:
  
 
show Constructive and destructive interference of sound waves.
 
show Constructive and destructive interference of sound waves.
−
|| Now click the '''Resume '''button three times to show different superpositions.
+
|| Now click the '''Resume''' button three times to show different superpositions.
 
|-
 
|-
 
|| Click on the Resume button and bring it to Destructive interference.
 
|| Click on the Resume button and bring it to Destructive interference.
Line 182: Line 179:
  
  
−
Here the waves are out of phase so they subtract each other and form a straight line.
+
Here the waves are out of phase.
 +
 
 +
So they subtract each other and form a straight line.
 
|-
 
|-
 
|| Click on '''Resume''' button.
 
|| Click on '''Resume''' button.
Line 191: Line 190:
  
  
−
It lies between the constructive and destructive superposition.
+
It lies between the constructive and destructive superpositions.
 
|-
 
|-
 
|| Click on '''Resume''' button.
 
|| Click on '''Resume''' button.
Line 197: Line 196:
 
|-
 
|-
 
|| Point to the wave.
 
|| Point to the wave.
−
|| This is constructive interference of the wave.
+
|| This is constructive interference of the waves.
  
−
 
+
This is the amplitude of the resulting standing wave.
−
Here the amplitude of the resulting standing wave is sum of both incident and reflected wave.
+
It is the sum of incident and reflected waves.
 
|-
 
|-
 
|| Continuously click on '''Resume '''button to show the three steps.
 
|| Continuously click on '''Resume '''button to show the three steps.
−
|| For the time period '''T/8''', one cycle takes three steps to complete.  
+
|| For the time period '''T by 8''', one '''cycle''' takes three steps to complete.  
  
  
−
T/8 means 1/8th of the total time period.
+
'''T by 8''' means 1/8th of the total time period.
 
|-
 
|-
−
|| Select '''T/24 '''from the drop down.
+
|| Select '''T/24 ''' from the drop down.
  
 
Click on the''' Resume '''button
 
Click on the''' Resume '''button
Line 214: Line 213:
  
 
point to various superpositions.
 
point to various superpositions.
−
|| Let us select '''T/24 '''from the drop down.
+
|| Let us select '''T by 24 ''' from the drop-down.
  
  
−
Click on the''' Resume '''button continuously to see various superpositions.
+
Click on the ''' Resume '''button continuously to see various superpositions.
  
  
Line 223: Line 222:
 
|-
 
|-
 
|| Select T/4 and T/12 options >> click Resume button.
 
|| Select T/4 and T/12 options >> click Resume button.
−
|| You can try other options given in the drop down on your own.
+
|| You can try other options given in the drop-down on your own.
 
|-
 
|-
 
|| Point to''' N '''and '''A.'''
 
|| Point to''' N '''and '''A.'''
Line 229: Line 228:
 
|-
 
|-
 
|| Point to '''N '''and '''A'''.
 
|| Point to '''N '''and '''A'''.
−
|| Here''' N''' is a''' Node''' and '''A '''is an''' Antinode'''.
+
|| Here''' N''' is a''' Node''' and '''A''' is an''' Antinode'''.
 
|-
 
|-
−
|| '''Slide Number 10'''
+
|| '''Slide Number 8'''
  
 
'''Node and Antinode'''
 
'''Node and Antinode'''
  
−
'''Node '''is the point where the particles do not have any motion.
+
* '''Node '''is the point where the particles do not have any motion.
−
 
+
−
'''Antinode''' is the point where the particle oscillates with maximum amplitude.
+
−
 
+
−
 
+
  
 +
* '''Antinode''' is the point where the particle oscillates with maximum amplitude.
 
|| Let us define a '''Node''' and an '''Antinode.'''
 
|| Let us define a '''Node''' and an '''Antinode.'''
  
  
−
'''Node '''is the point where the particles do not have any motion.
+
*'''Node '''is the point where the particles do not have any motion.
  
  
−
'''Antinode''' is the point where the particle oscillates with maximum amplitude.  
+
*'''Antinode''' is the point where the particle oscillates with maximum amplitude.  
 
|-
 
|-
−
|| '''Slide Number 11'''
+
|| '''Slide Number 9'''
  
 
'''Assignment'''
 
'''Assignment'''
  
−
Using '''Reflection from free end''' option, show the formation of standing waves.
+
Using '''Reflection from free end''' option, show the formation of '''standing waves'''.
  
  
Line 270: Line 266:
 
Explain your observation.
 
Explain your observation.
 
|-
 
|-
−
||  
+
||
 
|| Let us move on to '''Standing longitudinal wave App'''.
 
|| Let us move on to '''Standing longitudinal wave App'''.
 
|-
 
|-
−
|| To open the''' App '''right click on '''standinglongitudinalwaves_en.htm '''file.
+
|| Right-click on '''standinglongitudinalwaves_en.htm''' file.
  
−
Select the option '''Open With Firefox Web Browser'''.
+
Select '''Open with Firefox Web Browser'''.
−
|| To open the''' App '''right click on '''standinglongitudinalwaves_en.htm '''file.
+
|| To open the''' App '''right-click on '''standinglongitudinalwaves_en.htm '''file.
  
−
Select the option '''Open With Firefox Web Browser'''.
+
Select the option '''Open with Firefox Web Browser'''.
 
|-
 
|-
 
|| Point to the '''App'''.
 
|| Point to the '''App'''.
Line 290: Line 286:
 
|-
 
|-
 
|| Point to the tube.
 
|| Point to the tube.
−
 
  
 
Point to the blue points.
 
Point to the blue points.
Line 296: Line 291:
  
  
−
The blue dots inside the tube represent the air molecules  
+
The blue dots inside the tube represent the air molecules.
 
|-
 
|-
 
|| Point to both the graphs in given sequence.
 
|| Point to both the graphs in given sequence.
 
|| Here we can see two plots.
 
|| Here we can see two plots.
  
−
'''Displacement of particles''' and '''Divergence from the average pressure'''.
+
'''Displacement of particles''' and '''Divergence from average pressure'''.
 
|-
 
|-
 
|| Point to both the X- axis.
 
|| Point to both the X- axis.
Line 330: Line 325:
  
 
Point to '''Lower''' and '''Higher '''buttons.
 
Point to '''Lower''' and '''Higher '''buttons.
−
|| Next, under '''Vibrational mode''' we see two buttons '''Lower '''and '''Higher'''.
+
|| Next, under '''Vibrational mode''' we see two buttons, '''Lower '''and '''Higher'''.
 
|-
 
|-
 
|| Point to the '''Lower''' buttons.
 
|| Point to the '''Lower''' buttons.
−
 
  
 
Point to show the '''fundamental'''.
 
Point to show the '''fundamental'''.
Line 339: Line 333:
  
  
−
The lowest vibrational mode of the system is known as '''fundamental'''.
+
The lowest '''vibrational mode''' of the system is known as '''fundamental'''.
  
  
−
Fundamental vibrational mode is the first harmonic followed by the higher harmonics.
+
'''Fundamental vibrational mode''' is the first harmonic followed by higher harmonics.
  
 
|-
 
|-
Line 353: Line 347:
 
|-
 
|-
 
|| Point to '''Wavelength''' and '''Frequency'''.
 
|| Point to '''Wavelength''' and '''Frequency'''.
−
|| The''' App '''calculates the '''Wavelength''' and '''Frequency '''based on the length of the tube.
+
|| The '''App''' calculates the '''Wavelength''' and '''Frequency '''based on the length of the tube.
  
 
|-
 
|-
 
|| Click on the '''Higher''' button till we get a''' 5<sup>th</sup> overtone'''.
 
|| Click on the '''Higher''' button till we get a''' 5<sup>th</sup> overtone'''.
−
|| Click the '''Higher '''button continuously to show 5 overtones for the six harmonical vibrations.
+
|| Click the '''Higher '''button continuously.
 +
 
 +
It shows 5 overtones for the six harmonical vibrations.
  
 
|-
 
|-
−
|| Click on '''F5''' key.
+
|| Press '''F5''' key.
−
|| Click on '''F5''' key on the keyboard to '''Reset '''the '''App'''.
+
|| Press '''F5''' key on the keyboard to reset the '''App'''.
  
 
|-
 
|-
Line 374: Line 370:
 
Molecules in the middle of the tube do not displace from the mean position.
 
Molecules in the middle of the tube do not displace from the mean position.
  
−
Therefore in the '''Displacement of particles''' graph, node is in the middle.
+
Therefore in the '''Displacement of particles''' graph, '''node''' is in the middle.
  
 
|-
 
|-
Line 382: Line 378:
 
Here particles oscillate with maximum amplitude.
 
Here particles oscillate with maximum amplitude.
  
−
Therefore antinode is present at the extreme ends of the x- axis.
+
Therefore '''antinode''' is present at the extreme ends of the X- axis.
  
 
|-
 
|-
Line 393: Line 389:
  
 
|-
 
|-
−
|| While editing point to graph and the tube.
+
|| Point to graph and the tube.
 
|| In the graph, movement of the pink wave shows the changes in the pressure.
 
|| In the graph, movement of the pink wave shows the changes in the pressure.
  
−
As the particles move towards the center, they get compressed, so pressure increases.
+
As the particles move towards the center, they get compressed.
 +
 
 +
So pressure increases.
  
 
When they move away pressure decreases.
 
When they move away pressure decreases.
Line 402: Line 400:
 
|-
 
|-
 
|| Click on '''one side open Form of tube '''radio button.
 
|| Click on '''one side open Form of tube '''radio button.
−
|| Under '''Form of tube, '''select '''one side open '''radio button.
+
|| Under '''Form of tube''', select '''one side open''' radio button.
  
 
|-
 
|-
Line 421: Line 419:
  
 
show the picture for which we have to calculate the wavelength.
 
show the picture for which we have to calculate the wavelength.
−
 
−
 
  
 
|| First let us define wavelength.
 
|| First let us define wavelength.
Line 437: Line 433:
  
 
|-
 
|-
−
|| '''Slide Number 12'''
+
|| '''Slide Number 10'''
  
 
'''Wavelength'''
 
'''Wavelength'''
Line 452: Line 448:
  
 
'''''λ=4L/n'''''
 
'''''λ=4L/n'''''
−
|| Mathematically we can write this as,
+
|| Mathematically we can write,
  
−
'''L = n/4 of lambda'''
+
'''L = n by 4 of lambda'''
  
  
 
here '''L''' is length of the tube and '''lambda''' is the wavelength.
 
here '''L''' is length of the tube and '''lambda''' is the wavelength.
  
−
‘ '''n'''’ can take values from 1 to n
+
‘'''n'''’ can take values from 1 to n.
  
 
By rearranging the equation we can write this as  
 
By rearranging the equation we can write this as  
  
−
'''lambda= 4L/n'''
+
'''lambda= 4L upon n'''
 
|-
 
|-
−
|| '''Slide Number 13'''
+
|| '''Slide Number 11'''
  
 
'''Wavelength'''
 
'''Wavelength'''
Line 473: Line 469:
  
  
−
'''''λ=<u>4 X 1</u><nowiki>= </nowiki>1.33 m'''''
+
'''''λ=(4 X 1)<nowiki>/3= </nowiki>1.33 m'''''
 +
 
  
−
'''''3'''''
+
|| Let us calculate the wavelength.
−
|| Now to calculate the wavelength, observe that the first overtone wave is three-fourth of the complete wave.
+
 
 +
The wavelength of the first overtone is three-fourth of the complete wave.
  
 
Here the value of n is 3.
 
Here the value of n is 3.
  
−
From the '''App, '''value of''' '''length of tube can be taken as L.
+
From the '''App, '''value of length of tube can be taken as '''L'''.
  
−
Therefore the calculated value of wavelength is 1.33 '''m'''.
+
Therefore the calculated value of wavelength is 1.33 '''metre'''.
  
 
This is the wavelength of first overtone mode of vibration.
 
This is the wavelength of first overtone mode of vibration.
 
|-
 
|-
−
|| '''Slide Number 14'''
+
|| '''Slide Number 12'''
  
 
'''Frequency'''
 
'''Frequency'''
Line 494: Line 492:
 
It is measured in '''hertz (Hz)'''.
 
It is measured in '''hertz (Hz)'''.
  
−
'''''f=c/λ'''''
+
'''f=c/λ'''
  
−
''λ is wavelength ''
+
'''λ''' is wavelength
  
−
''c is speed of sound wave''
+
'''c''' is speed of sound wave
 
|| Now we will calculate the frequency of the wave.
 
|| Now we will calculate the frequency of the wave.
  
Line 504: Line 502:
  
  
−
It is measured in hertz (Hz).
+
It is measured in '''hertz (Hz)'''.
  
  
 
Frequency is calculated using the formula.
 
Frequency is calculated using the formula.
  
−
'''''f=c/λ'''''
+
'''f=c/λ'''
  
−
''λ is wavelength and ''
+
'''λ''' is wavelength and  
  
−
''c is speed of sound wave''
+
'''c''' is speed of sound wave
 
|-
 
|-
 
|| Point to the value in the '''App'''.
 
|| Point to the value in the '''App'''.
−
|| The''' App '''has given the value for speed of sound wave as 343.5 '''m/s '''at 20 degree celsius.
+
|| The''' App ''' shows the value of speed of sound wave as 343.5 '''metre per second '''at 20 '''degree Celsius'''.
 
|-
 
|-
 
|| Cursor to show the wave for which frequency has to be calculated.
 
|| Cursor to show the wave for which frequency has to be calculated.
Line 523: Line 521:
 
|| Show the picture
 
|| Show the picture
  
−
''f=c/λ''
+
'''f=c/λ'''
  
−
''<nowiki>=</nowiki>''343.5 / 1.33
+
'''<nowiki>=</nowiki>343.5 / 1.33'''
  
 
<nowiki>= </nowiki>258.27 Hz
 
<nowiki>= </nowiki>258.27 Hz
Line 534: Line 532:
 
This value is comparable to the value shown in the '''App'''.
 
This value is comparable to the value shown in the '''App'''.
 
|-
 
|-
−
|| '''Slide Number 15'''
+
|| '''Slide Number 13'''
  
 
'''Tabular Column'''
 
'''Tabular Column'''
  
−
|| Let us make a tabular column to show the wavelength and frequency for 6 harmonical modes.
+
||Make a tabular column to show the wavelength and frequency for 6 harmonical modes.
 
|-
 
|-
 
|| Click on''' Higher'''.
 
|| Click on''' Higher'''.
 
|| Click on the '''Higher '''button to go to next harmonic.
 
|| Click on the '''Higher '''button to go to next harmonic.
 
|-
 
|-
−
|| '''Slide Number 16'''
+
|| '''Slide Number 14'''
  
 
'''Tabular Column '''
 
'''Tabular Column '''
  
 
Show the tabular column with values
 
Show the tabular column with values
−
|| Similarly I have calculated the values of frequency and wavelength for higher harmonics.
+
|| Similarly I have calculated frequency and wavelength for higher harmonics.
 
|-
 
|-
−
|| '''Slide Number 17'''
+
|| '''Slide Number 15'''
  
 
'''Assignment'''
 
'''Assignment'''
Line 557: Line 555:
 
|| As an assignment
 
|| As an assignment
  
−
Change the length of the tube to 8 m.
+
Change the length of tube to 8 metre.
  
 
Calculate the wavelength and frequency for different vibrational modes.
 
Calculate the wavelength and frequency for different vibrational modes.
 
|-
 
|-
−
|| '''Slide Number 18'''
+
|| '''Slide Number 16'''
  
 
'''Assignment'''
 
'''Assignment'''
  
−
Change the '''Form of tube''' to '''both sides closed '''and''' '''explain the graphs.
+
Change the '''Form of tube''' to '''both sides closed ''' and explain the graphs.
 
|| Another assignment.
 
|| Another assignment.
  
−
Change the '''Form of tube''' to '''both sides closed '''and''' '''explain the graphs.
+
Change the '''form of tube''' to '''both sides closed ''' and explain the graphs.
  
 
|-
 
|-
−
|| '''Slide Number 19'''
+
|| '''Slide Number 17'''
  
 
'''Summary'''
 
'''Summary'''
Line 579: Line 577:
 
Using these '''Apps''' we have,
 
Using these '''Apps''' we have,
  
−
* Demonstrated the formation of a standing wave.
+
* Formed a standing wave.
−
* Explained the formation of nodes and antinodes.
+
−
* Demonstrated harmonics of a standing wave.
+
  
−
|-
+
* Formed nodes and antinodes.
−
|| '''Slide Number 20'''
+
  
−
'''Summary'''
+
* Viewed various types of harmonics of a standing wave.
  
−
|| Calculated the wavelength and frequency of standing waves.
+
* Calculated the wavelength and frequency of standing waves.
  
 
|-
 
|-
−
|| '''Slide Number 21'''
+
|| '''Slide Number 18'''
  
 
'''Acknowledgement'''
 
'''Acknowledgement'''
  
−
These Apps were created by Walter-fendt and his team.
+
These '''Apps''' were created by '''Walter-fendt''' and his team.
−
|| These '''Apps '''were created by Walter-fendt and his team.
+
|| These '''Apps '''were created by '''Walter-fendt''' and his team.
  
 
|-
 
|-
−
|| '''Slide Number 22'''
+
|| '''Slide Number 19'''
  
 
'''About the Spoken Tutorial project.'''
 
'''About the Spoken Tutorial project.'''
Line 607: Line 602:
 
Please download and watch it.
 
Please download and watch it.
 
|-
 
|-
−
|| '''Slide Number 23'''
+
|| '''Slide Number 20'''
  
 
'''Spoken Tutorial workshops.'''
 
'''Spoken Tutorial workshops.'''
  
−
||The&nbsp;'''Spoken Tutorial Project&nbsp;'''team,
+
||The '''Spoken Tutorial Project''' team conducts workshops and gives certificates.
−
 
+
−
conducts workshops and gives certificates
+
  
 
For more details, please write to us.
 
For more details, please write to us.
 
|-
 
|-
−
|| '''Slide Number 24'''
+
|| '''Slide Number 21'''
  
 
'''Forum for specific questions:'''
 
'''Forum for specific questions:'''
Line 632: Line 625:
 
|| Please post your timed queries on this forum.
 
|| Please post your timed queries on this forum.
 
|-
 
|-
−
|| '''Slide Number 25'''
+
|| '''Slide Number 22'''
  
 
'''Acknowledgement'''
 
'''Acknowledgement'''

Latest revision as of 12:31, 5 June 2020

Visual Cue Narration
Slide Number 1

Title Slide

Welcome to the spoken tutorial on Sound Waves.
Slide Number 2

Learning Objectives

In this tutorial we will,

Form a standing wave.

Form nodes and antinodes.

View various types of harmonics of a standing wave.

Calculate the wavelength and frequency of standing waves.


Slide Number 3

System Requirements

Here I am using,
  • Ubuntu Linux OS version 16.04
  • Firefox web browser version 62.0.3
Slide Number 4

Pre-requitsites

https://spoken-tutorial.org

To follow this tutorial learner should be familiar with Apps on Physics.

For the pre-requisite tutorials please visit this site.

Slide Number 5

Learning Goals

Calculate the wavelength and frequency of standing waves.
Slide Number 6

Link for Apps on physics

https://www.walter-fendt.de/html5/phen/

Use the given link to download the Apps.
Point to the file in the Downloads folder I have downloaded the Apps to my Downloads folder.
Slide Number 7

Apps on Physics

In this tutorial we will use,

Standing Wave and Standing Longitudinal Waves Apps.

Right-click on standingwavereflection_en.htm file.

Select option Open With Firefox Web Browser option.

Right-click on standingwavereflection_en.htm file.

Select the option Open with Firefox Web Browser.

Standing Wave App opens in the browser.

Point to the radio buttons,

Reflection from a fixed end and Reflection from a free end.

In the green panel under Reflection we have two radio buttons.
  • from a fixed end and
  • from a free end.
Point to Reflection from a fixed end. By default Reflection from a fixed end is selected.
Point to Reset and Start button. Below these radio buttons you can see, Reset and Start buttons.
Point to Start >> Pause >> Resume. Start button is a toggle for Start, Pause and Resume.
Point to the three check-boxes

Incidenting wave

Reflected wave and

Resultant standing wave.

At the bottom of the green panel you can see
  • Incidenting wave
  • Reflected wave and
  • Resultant standing wave check-boxes.
Point to the check-boxes. These check-boxes are selected by default.
Click Start button. Click on the Start button.
Move the cursor to show oscillations on the string. On the yellow panel, observe the propagation of a wave in a string.


The red wave is the Incidenting wave.

Point the cursor to show the reflection from the fixed end.


Point to the blue Reflected wave.

The blue wave is the Reflected wave.


Observe that the reflected wave has a phase change of 180 degrees.

Point to show the amplitude. Here the incident and reflected waves have the same amplitude.
Uncheck the Reflected wave. Let us uncheck the Reflected wave.


If we uncheck any of the check-boxes, we cannot see the corresponding wave.

Click on the Reflected wave check-box Click the Reflected wave check-box to make it visible again.
Click on the Pause button. Click on the Pause button to stop the propagation of the waves.
Point to the resultant wave. Here is the resultant standing wave.
Pause the App when it shows this image. This wave is formed due to the superposition of incident and reflected waves.


The resultant wave is the constructive superposition of the waves.

Cursor on the waves. Now I will show the superposition of waves in a step-by-step manner.
Click on Single step radio button.

Point to the animation after clicking.

Click on the Single steps radio button to show the animation step-by-step.
Click on the drop down to see the different time period.


Point to T/8.

Here a drop down to show various time periods is seen.


By default it is T by 8.


We will leave it as it is.

Click 3 times on Resume button.

show Constructive and destructive interference of sound waves.

Now click the Resume button three times to show different superpositions.
Click on the Resume button and bring it to Destructive interference. This is destructive interference of sound waves.


Here the waves are out of phase.

So they subtract each other and form a straight line.

Click on Resume button. Click on Resume button again.
Point and show the intermediate superposition. This is an intermediate superposition of waves.


It lies between the constructive and destructive superpositions.

Click on Resume button. Again click on the Resume button.
Point to the wave. This is constructive interference of the waves.

This is the amplitude of the resulting standing wave. It is the sum of incident and reflected waves.

Continuously click on Resume button to show the three steps. For the time period T by 8, one cycle takes three steps to complete.


T by 8 means 1/8th of the total time period.

Select T/24 from the drop down.

Click on the Resume button


point to various superpositions.

Let us select T by 24 from the drop-down.


Click on the Resume button continuously to see various superpositions.


Observe that one superposition cycle now takes five steps.

Select T/4 and T/12 options >> click Resume button. You can try other options given in the drop-down on your own.
Point to N and A. After the reflection from the fixed end, you can see A and N on the string.
Point to N and A. Here N is a Node and A is an Antinode.
Slide Number 8

Node and Antinode

  • Node is the point where the particles do not have any motion.
  • Antinode is the point where the particle oscillates with maximum amplitude.
Let us define a Node and an Antinode.


  • Node is the point where the particles do not have any motion.


  • Antinode is the point where the particle oscillates with maximum amplitude.
Slide Number 9

Assignment

Using Reflection from free end option, show the formation of standing waves.


Observe the reflection by selecting various time period options.


Explain your observation.

As an assignment

Using Reflection from free end option, show the formation of standing waves.


Observe the reflection by selecting various time period options.


Explain your observation.

Let us move on to Standing longitudinal wave App.
Right-click on standinglongitudinalwaves_en.htm file.

Select Open with Firefox Web Browser.

To open the App right-click on standinglongitudinalwaves_en.htm file.

Select the option Open with Firefox Web Browser.

Point to the App. The App opens in the browser.
Highlight the 1st line from the paragraph. Here is the information related to the App interface.
Scroll down to see the interface. Scroll down to see the interface completely.
Point to the tube.

Point to the blue points.

This interface shows a tube filled with air molecules.


The blue dots inside the tube represent the air molecules.

Point to both the graphs in given sequence. Here we can see two plots.

Displacement of particles and Divergence from average pressure.

Point to both the X- axis.

Point to Δx.

Point to Δp.

X axis represents the length of the tube.


Δ(delta)x is the change in displacement of molecules from the equilibrium position.


Δ(delta)p is the Divergence from average pressure.

Point to pink and red waves. Observe the pink and red waves.

They show the instantaneous movement of air molecules.

Point to the Form of tube and move the cursor to show the different radio buttons. In the green panel, under the heading Form of tube, we have three radio buttons.
Point to the default selected form. By default both sides open radio button is selected.
Point to the Vibrational mode.

Point to Lower and Higher buttons.

Next, under Vibrational mode we see two buttons, Lower and Higher.
Point to the Lower buttons.

Point to show the fundamental.

By default, the App shows the lowest Vibrational mode.


The lowest vibrational mode of the system is known as fundamental.


Fundamental vibrational mode is the first harmonic followed by higher harmonics.

Point to Length of tube edit box. We can change the Length of the tube in this box.
Point to Length of tube. Length of the tube can be varied between 1 meter to 10 meters.
Point to Wavelength and Frequency. The App calculates the Wavelength and Frequency based on the length of the tube.
Click on the Higher button till we get a 5th overtone. Click the Higher button continuously.

It shows 5 overtones for the six harmonical vibrations.

Press F5 key. Press F5 key on the keyboard to reset the App.
Point to the tube.

Move the cursor to show the particles at the middle.

Move the cursor to show the particles at extreme positions.

Observe the motion of air molecules.

Molecules in the middle of the tube do not displace from the mean position.

Therefore in the Displacement of particles graph, node is in the middle.

Show the movement of particles and then point to the graph Observe that particles at the extreme positions are oscillating in and out.

Here particles oscillate with maximum amplitude.

Therefore antinode is present at the extreme ends of the X- axis.

Move the cursor to 2nd graph. Let us move to the second graph.
Cursor on the interface. Observe the movement of particles inside the tube and graph simultaneously.
Point to graph and the tube. In the graph, movement of the pink wave shows the changes in the pressure.

As the particles move towards the center, they get compressed.

So pressure increases.

When they move away pressure decreases.

Click on one side open Form of tube radio button. Under Form of tube, select one side open radio button.
Cursor on the tube. Observe the movement of particles in this form of the tube.
Point to the closed end. Here particles at the closed end are not moving.

Therefore the pressure is maximum at this end.

Cursor on the interface. Let us calculate the wavelength in this form of the tube.
Define Wavelength in a text-box.

show the picture for which we have to calculate the wavelength.

First let us define wavelength.

Wavelength is the distance between two consecutive peaks.

Click on the Higher button.

Point to the 1st overtone

Click on the Higher button to show the first overtone.

We have to calculate the wavelength of first overtone wave.

Slide Number 10

Wavelength


L = (n/4)x λ

L is length of tube

λ is wavelength

n= 1,2,3,......n


λ=4L/n

Mathematically we can write,

L = n by 4 of lambda


here L is length of the tube and lambda is the wavelength.

‘n’ can take values from 1 to n.

By rearranging the equation we can write this as

lambda= 4L upon n

Slide Number 11

Wavelength


λ=4L/n


λ=(4 X 1)/3= 1.33 m


Let us calculate the wavelength.

The wavelength of the first overtone is three-fourth of the complete wave.

Here the value of n is 3.

From the App, value of length of tube can be taken as L.

Therefore the calculated value of wavelength is 1.33 metre.

This is the wavelength of first overtone mode of vibration.

Slide Number 12

Frequency

The number of complete oscillations per second is known as the frequency of a sound wave.

It is measured in hertz (Hz).

f=c/λ

λ is wavelength

c is speed of sound wave

Now we will calculate the frequency of the wave.

The number of complete oscillations per second is the frequency of a sound wave.


It is measured in hertz (Hz).


Frequency is calculated using the formula.

f=c/λ

λ is wavelength and

c is speed of sound wave

Point to the value in the App. The App shows the value of speed of sound wave as 343.5 metre per second at 20 degree Celsius.
Cursor to show the wave for which frequency has to be calculated. Let us calculate the frequency of the same wave.
Show the picture

f=c/λ

=343.5 / 1.33

= 258.27 Hz

Substitute the values for the above formula from the App.

The value for the frequency is 258.27 Hertz.

This value is comparable to the value shown in the App.

Slide Number 13

Tabular Column

Make a tabular column to show the wavelength and frequency for 6 harmonical modes.
Click on Higher. Click on the Higher button to go to next harmonic.
Slide Number 14

Tabular Column

Show the tabular column with values

Similarly I have calculated frequency and wavelength for higher harmonics.
Slide Number 15

Assignment

Show the empty table.

As an assignment

Change the length of tube to 8 metre.

Calculate the wavelength and frequency for different vibrational modes.

Slide Number 16

Assignment

Change the Form of tube to both sides closed and explain the graphs.

Another assignment.

Change the form of tube to both sides closed and explain the graphs.

Slide Number 17

Summary

Let us summarize.

Using these Apps we have,

  • Formed a standing wave.
  • Formed nodes and antinodes.
  • Viewed various types of harmonics of a standing wave.
  • Calculated the wavelength and frequency of standing waves.
Slide Number 18

Acknowledgement

These Apps were created by Walter-fendt and his team.

These Apps were created by Walter-fendt and his team.
Slide Number 19

About the Spoken Tutorial project.

The video at the following link summarizes the Spoken Tutorial project.

Please download and watch it.

Slide Number 20

Spoken Tutorial workshops.

The Spoken Tutorial Project team conducts workshops and gives certificates.

For more details, please write to us.

Slide Number 21

Forum for specific questions:

Do you have questions in THIS Spoken Tutorial?

Please visit this site

Choose the minute and second where you have the question.

Explain your question briefly.

Someone from our team will answer them.

Please post your timed queries on this forum.
Slide Number 22

Acknowledgement

Spoken Tutorial Project is funded by MHRD, Government of India.
This is Himanshi Karwanje from IIT-Bombay.

Thank you for joining.

Contributors and Content Editors

Karwanjehimanshi95, Madhurig, Nancyvarkey, Snehalathak

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