Waves and sounds
-
Upload
gauravlath1997 -
Category
Technology
-
view
1.324 -
download
1
description
Transcript of Waves and sounds
![Page 1: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/1.jpg)
Waves and sounds
![Page 2: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/2.jpg)
What is a wave?
- A wave is a disturbance that travels through a medium from one location to another
- A wave is the motion of disturbance- The frequency of a wave is its most basic factor
which doesn’t change when entering one medium through another.
![Page 3: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/3.jpg)
Types of WavesWAVES
ELCTROMAGNETIC WAVES
MECHANICAL WAVES
MATTER WAVES
TRANSEVERSE WAVES
LONGITUDNAL WAVES
SURFACE WAVES ELECTROMAGNETIC
SPECTRUM
![Page 4: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/4.jpg)
Mechanical Waves-Mechanical waves are produced by a disturbance .
-It requires a medium to travel. Common examples include air, water and sound.
- There are 3 types: Transverse, Longitudinal and Surface
![Page 5: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/5.jpg)
Transverse WavesIn transverse waves the direction of the disturbance is perpendicular To that of the direction of travel of the wave.
They also occur when the source disturbance of the wave follows a periodic motion.
They create crests and troughs while travelling and show polarization.
![Page 6: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/6.jpg)
Longitudinal Waves
In this type of a mechanical wave the direction of disturbanceIs parallel to the direction of the motion of the waves.
![Page 7: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/7.jpg)
Some DefinitionsPolarization : It is the process in which the wave vibrates in only one plane.Reflection: When a wave gets reflected back upon entering a medium is known as reflection.Refraction: When switching from one medium to another when the speed of the wave changes and not the frequency.Diffraction: The spreading of waves when it enters through a small slit is known as diffraction.Wave fronts: It gives the position of the waves at a certain time
![Page 8: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/8.jpg)
Longitudinal waves
• Vibrations parallel to direction of motion
• They produce rare faction and compression
• They do no show polarization
Transverse waves• Vibrations at right
angle to the direction of motion.
• They create crests and troughs
• They do show polarization.
![Page 9: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/9.jpg)
Measuring A Wave The wavelength of a wave is the measure of one crest and one troughWhich Is represented by the Greek letter lambda.
![Page 10: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/10.jpg)
A displacement – distance graph can also be used
![Page 11: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/11.jpg)
The most important equation
Speed of wave = frequency X wavelength
![Page 12: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/12.jpg)
• Light, microwaves, x-rays, and TV and radio transmissions are all kinds of electromagnetic waves. They are all the same kind of wavy disturbance that repeats itself over a distance called the wavelength.
Electromagnetic Radiation
![Page 13: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/13.jpg)
At vacuum they travel with the speed of light, i.e at 300000000 m/s ; They show polarization and Diffraction , thus they are transverse in nature; they obey the general equation; they carry energy From one place to another and can be absorbed by matter to cause heating and other effects;
![Page 14: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/14.jpg)
Radio WavesRadio waves are the waves with the longest wavelength and the lowest Frequency, they are used to carry sound, pictures and other informationOver a long distance, they are reflected by small electrically charged Particles present in the ionosphere which makes long distance radio Reception possible. We use them in our radios , phones and TV’s which All usually have antennae’s on them.
![Page 15: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/15.jpg)
MicrowavesThis comes next in the spectrum. Their most common use is in the microWave. They help in cooking the food, they are also used in mobile phonesAnd TV’s. They are used for radar detection. They are the only waves Which can penetrate light rain, haze, snow, clouds and smoke and canTherefore be used in space for taking images of the Earth. These can haveWavelengths measuring a few centimeters to a foot in length.
![Page 16: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/16.jpg)
InfraredInfrared is emitted by all living organisms in large or small quantity, theycan have wavelengths as long as a pin or as short as a cell. The longerInfrared rays are thermal, i.e. we feel warm due to their emission.The short infrared rays on the other hands are used in devices such as The remote control. They can also be used to cook food faster. We can Take infrared sensitive photos using special cameras.
![Page 17: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/17.jpg)
Visible Light
![Page 18: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/18.jpg)
UltravioletThese rays are what cause are skin tan and some extreme cases skinCancer, but they also produce vitamins. The sun emits these rays the Most. They may not be visible to our eyes but the bumblebee and Other likewise organisms can. They are also used to detect invisible Signatures and causes fluorescent clothes to flouresce.
![Page 19: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/19.jpg)
X-RaysThe most common use of these rays are in X-Ray machines, they can Penetrate objects like clothes to give images of the bones.
![Page 20: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/20.jpg)
Gamma RaysThese are the rays with the shortest wavelengths and highest frequency.Gamma rays are used to kill cells, like the cancerous cells. They are alsoUsed to clean surgical instruments.
![Page 21: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/21.jpg)
Sound WavesIt is a type of longitudinal wave which cannot like light waves travelIn vacuum and is best transmitted by solids followed by liquids and Gases. It displays properties of interference and diffraction.
They are well reflected from hard and flat surfaces causing echo.If the surface is nearer than 15m than the echo joins up with the originalSound, this is called reverberation.
![Page 22: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/22.jpg)
The Speed of SoundThe speed of sound varies depending on the material it travels through.In:AIR(0 degree C ): 330m/s ( for rise of every 1 degree the speed increases by 0.61 m/s)WATER : 1400m/sCONCRETE : 5000m/sSTEEL : 6000m/s
We can find the speed using the general equation and to find the Wavelength we can use the formula Wavelength = velocity /frequency
![Page 23: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/23.jpg)
More about soundHearing capacity of humans is sound waves of frequency with 20Hz to 20,000 Hz.
The 3 properties of sound waves are:1)Pitch – Directly proportional to the frequency2) Loudness – Directly Proportional to the amplitude3) Quality – No instrument except a tuning fork emits a pure note and They have a fundamental note mixed with other notes which are overtones and are exact multiples of the fundamental notes.
Frequencies of sound waves above 20,0000 Hz are called ultrasonic, andObjects with speed slower than sound are called subsonic and vice versaAre called supersonic.
![Page 24: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/24.jpg)
Test YourselfQ.1. Sound is faster in ? Explain
-Air- Water- solid
![Page 25: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/25.jpg)
Q2. The approximate speed of sound in air is________ m/s
-5000- 3 X 100000000
- -1600- -330
![Page 26: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/26.jpg)
Q3. The number of sound vibrations per second is called _______.
- Frequency- Amplitude- Time Period
![Page 27: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/27.jpg)
Q4. Explain Reverberation
![Page 28: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/28.jpg)
Q5. The Greek letter _______ is usually used as a symbol to denote the wavelength. λ (lambda) κ (kappa) δ (delta)
![Page 29: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/29.jpg)
Q6. Name any three differences that exist between
Longitudinal and transverse waves. Also, is sound in vacuum transverse
Or longitudinal?
![Page 30: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/30.jpg)
Q7. If the temperature of a lab is kept at45 degrees Celsius what is
The speed of sound ?
![Page 31: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/31.jpg)
Q8. Identify the wave used in the following
And why are the antennae’s size different?
![Page 32: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/32.jpg)
Q9. A physics student sitti ng near the bonfire
Is feeling warm, which rays effects are these?
![Page 33: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/33.jpg)
Q10. Identify the wave whoseLight sensitive photo this is and
Which are the more energetic areas?
![Page 34: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/34.jpg)
Bonus QuestionsQ. Suggest the properties of Sound that prove that it is a wave
Q. What are the factors that affect the speed of sound in any medium
Q. If a nurse cleans the surgical instruments just before a surgery , which ray does she use?
![Page 35: Waves and sounds](https://reader033.fdocuments.us/reader033/viewer/2022052619/55552d13b4c905b9318b5c3e/html5/thumbnails/35.jpg)
Made By:Yashvi Turakhia Shivani Mangal
IX CIE