Is it always convenient to use Newton's laws? Jet engine. Octopus. Baron Munchausen. What kind of movement is called reactive? Jet propulsion. Story. Modern technologies production of launch vehicles. Body movement. Cyrano de Bergerac. Jet motion in nature. Rocket. Konstantin Eduardovich Tsiolkovsky (1857-1935).
"Nuclear Reactor Principle" - Use of nuclear reactors. Types of reactors. What is the critical mass of uranium 295. What is the critical mass of uranium. Nuclear reactor. Essential elements nuclear reactor. What energy transformations occur in a nuclear reactor. Energy conversion. Repetition. Fast neutron reactors. The reactor is controlled using rods. What particles are involved in the fission of uranium nuclei.
"Ohm's Law for a Circuit" - An experiment proving that the resistance of a conductor decreases. Ohm's law. Let us mentally select a small cylindrical volume in the vicinity of the point. Experimental verification of the nature of the relationship between current and voltage. The conductor's resistance decreases as it cools. Concentration of free electrons in a metal. Analysis of the experimental results. Voltage and current measurement table for incandescent lamp.
“Technologies of the Future” - Forecast for the development of the market for nanotechnology products for 2015. What they are offering now. A technology innovation zone is being built in Tomsk Akademgorodok. Creation of micro - nano - electromechanical systems. Companies that do not want to build separate buildings for themselves. "There's still plenty of room down there." XXI century will be the century of nanoscience and nanotechnology. Nanobeginning. Nanotechnology tomorrow. A new direction in technology - . Nanotechnology today.
“The “Nature of Light” Physics” - Photon. Properties electromagnetic waves. Electromagnetic nature of light. Christiaan Huygens. Thus, light has particle-wave properties. Einstein (1879–1965). Isaac Newton. 1642 -1727. Views on the nature of light in the 17th-19th centuries. The transition of energy from light to matter or from matter to light obeys the relation E = h?. Municipal budget educational institution « high school No. 46" of the city of Ryazan.
“Nuclear Energy Safety” - Nuclear power plants have more opportunities for energy production. Nuclear power. From the history nuclear energy. Safety. Nuclear power plants. The decay reaction of uranium nuclei. Diagram of the operation of a boiling nuclear reactor. The benefits and harms of nuclear energy. Nuclear power plants on the map of Russia. Thermonuclear fusion. Diagram of a boiling nuclear reactor. The harm of nuclear energy. Nuclear icebreakers. Nuclear reactor.
SOUND WAVES
The world of sounds is so diverse,
Rich, beautiful, diverse,
But we are all tormented by the question: Where do sounds come from?
Why do our ears delight everywhere?
It's time to think seriously.
Cause of the sound? - vibration (oscillations) of bodies, although these vibrations are often invisible to our eyes.
Sound sources are physical bodies that vibrate, i.e. tremble or vibrate at a frequency
from 16 to 20,000 times per second. The vibrating body can be solid, such as a string or Earth's crust, gaseous, for example, a stream of air in a wind musical instrument or in a whistle, or liquid, for example, waves on water.
Vibrations occur around the oscillating body environment, which spread in space.
Sound is mechanical elastic waves, spreading in gases, liquids, solids.
Waves that cause the sensation of sound, with frequency from 16 Hz to 20,000 Hz called
sound waves (mainly longitudinal).
DO IT YOURSELF!
If you bring a bead on a string to a glass or glass jar and strike it, for example,
pencil along the wall of the glass, we will see the vibrations of the bead and hear its ringing.
TO HEAR THE SOUND
required:
1. sound source;
2. elastic medium between it and the ear;
3. a certain range of vibration frequencies of the sound source - between 16 Hz and 20 kHz,
sufficient power of sound waves for the ear to perceive.
SOUND CHARACTERISTICS
Volume.
.
Loudness depends on the amplitude of vibrations in the sound wave.
The unit of sound volume is 1 Bel (in honor of Alexander Graham Bell, inventor of the telephone). The volume of a sound is 1 B if its power is 10 times the threshold of audibility.
In practice, loudness is measured in decibels (dB).
1 dB = 0.1B. 10 dB – whisper; 20–30 dB – noise standard in residential premises;
50 dB – medium volume conversation;
70 dB – typewriter noise;
80 dB – noise of a running truck engine;
120 dB – noise of a running tractor at a distance of 1 m
130 dB – pain threshold.
Sound louder than 180 dB can even cause eardrum rupture.
Pitch.
Determined by the vibration frequency of the sound source.
The sounds of the human voice are divided by pitch into several ranges:
bass – 80–350 Hz,
baritone – 110–149 Hz,
tenor – 130–520 Hz,
treble – 260–1000 Hz,
soprano – 260–1050 Hz,
coloratura soprano – up to 1400 Hz.
Frequency spectrum of sounds of musical instruments.
According to legend, Pythagoras arranged all musical sounds in a row, breaking this row into parts - octaves - and the octave into 12 parts (7 basic tones and 5 semitones). There are 10 octaves in total; usually 7–8 octaves are used when performing musical works. Sounds with a frequency of more than 3000 Hz are not used as musical tones; they are too sharp and shrill.
FREQUENCY RANGE OF SOUND PERCEIVED BY ANIMALS
BOOKSHELF
INTERESTING PHENOMENA!
ABOUT SOUNDS IN LITERATURE...
(Noise is a jumbled mixture of musical sounds.)
DO NOT MAKE NOISE!
Did we make any noise?
Well, Andryusha knocked barely
Hammer on an iron pipe,
I played softly on my lip,
Eight-fifths size observing,
Tanya slammed the barn door,
Sasha moved a stone across the glass,
Tolya was hitting a saucepan in the corner.
Brick! But quietly and rarely.
"Do not make noise!" - said the neighbor,
And no one thought to make noise.....
Al. Kushner.
Why does the drum sound?
One day, the leader Hawkeye and the shaman Snaketongue met.
"Why does the drum sound?" - asked the shaman.
The leader quickly replied: “Because he was hit.”
The shaman responded very quickly: “The sound after the blow lasts noticeably longer than the blow itself.”
Immediately the leader and shaman demanded the largest drum.
First, the leader struck and the shaman touched the drum skin, then vice versa.
Eventually, they noticed that the skin was shaking, and when it shook, a sound was heard.
Here the leader, who was as good at guessing as a shaman at riddles, expressed the Great Conjecture:
EVERYTHING THAT SOUNDS SHAKES!!!
At the same time, the leader screamed with delight so that the shaman’s ears began to ring.
Unconscious from pain, the shaman grabbed the leader by the throat. My throat was shaking!
The shaman released the leader and took the Guard Jaguar, who was purring at the entrance, by the scruff of the neck.
The scruff of the neck was shaking!
Then the leader stopped yelling and gave out the second Great Guess:
EVERYTHING IS SOUNDING!!!
Instead of asking an insidious question, the shaman brought his convulsively clenched fist closer to the leader’s nose.
The fist (and the whole hand) trembled - but did not sound. The second great guess had to be corrected:
NOT EVERYTHING SOUNDS TREMBLING!
Meanwhile, the shaman had another insidious question:
"How to tremble to sound?"
The leader remembered a recent battle: if a long arrow is pierced into a tree trunk, it trembles silently, if a short one, it sounds. The shaman pulled out the longest arrow, pressed the feathered end to a flat stone, and the leader bent the sharp end down - and immediately released it.
Then he made the free end shorter and let it go again.
The leader’s answer, it was not for nothing that he was called Hawkeye, was as follows:
"The arrow begins to sound when its trembling is no longer noticeable to the eye - it is so frequent."
The shaman asked the leader to switch places: now the leader was holding the feathered end of the arrow, and
the shaman deflected and released the tip. Shaman Snaketongue was weaker than the leader, and each time he deflected the tip less strongly. How did the sound change?
HORN - SOUND AMPLIFIER
Often in competitions, when a coach or judge needs to communicate something to an athlete from a long distance, a bullhorn is used. This can be a rather complex device - a megaphone, but you can get by with a simple newspaper rolled up in a bag. You can make horns from large sheets of whatman paper. If you place two such horns in a classroom at opposite walls, then you can talk with their help in a whisper.
LISTENING TO MUSIC!
To demonstrate how a horn amplifies sound, make from thick paper
a small speaker, and stick it into the thin end perpendicular to the surface of the paper
sewing needle. Paste pencil in hole records of some kind of music.
Place the sharp end of the pencil with the plate against the table surface and begin to rotate the plate, quickly turning the pencil. With your other hand, place the tip of the horn needle on the sound groove of the record. Listen! There should be sound!
TRY!
And if you take 2 thin rubber tubes insert into the narrow end of the horn, wrap it with insulating tape, and insert the free ends of these tubes into both ears, then with such a simple device distant and weak sounds will be heard much better.
For example, remember why a doctor needs a stethoscope?
What did E.K. Tsiolkovsky use to compensate for his deafness?
Why does a person put his palm to his ear, trying to make out hard-to-hear sounds?
WOW!
They found that when it becomes difficult for a plant to extract water from dry soil,
the plant stem begins make ultrasonic noises. Attached to the stems
special microphones, you can pick up these noises and turn on the sprinklers
only when the plants themselves require it
The sound of snoring can reach 69 decibels, which is comparable to the sound jackhammer.
___
The loudest noise obtained in laboratory conditions was equal to 210 dB. It was received
due to the reflection of sound by a reinforced concrete test stand designed to test a rocket at the US Space Flight Center in 1965. A sound wave of such strength could drill holes in solid materials. The noise was heard within 161 km.
The highest note received has a frequency of 60 gigahertz. It was generated by a laser beam aimed at a sapphire crystal in the USA in 1964.
The quietest place- This "Dead Room" at the Bell Telephone Systems Laboratory in the USA, it is the most sound-absorbing room in the world, in which 99.98% of reflected sound disappears.
DO IT YOURSELF!
Homemade telephone from thread and matchboxes.
Take it 2 matchboxes(or any other boxes of suitable sizes: powder, tooth powder, paper clips) and a thread several meters long (possibly for the entire length of the school class). Pierce the bottom of the box with a needle and thread and tie a knot in the thread so that it does not jump out. So Thus, both boxes will be connected using a thread. Two people participate in a telephone conversation: one speaks into the box, like into a microphone, the other listens, putting the box to his ear. The thread should be taut during the conversation and should not touch any objects, including the fingers that hold the boxes. If you touch finger to the thread, the conversation will immediately stop. Why?
If you take several empty identical bottles, line them up and fill with water(the first one is filled with a small amount of water, the subsequent ones are filled incrementally, and the last one is filled to the top), then you will get a musical percussion instrument. By hitting the bottles with a spoon, we will make the water vibrate. The sounds from the bottles will vary in pitch.
We take a cardboard tube, insert a cork with a knitting needle inserted into it like a piston and, moving the piston, blow into the edge of the tube. The flute sounds!
We take a box with wrinkle-resistant edges, put rubber bands on it (the tighter they wrap around the box, the better), and the harp is ready! Picking out the rubber bands like strings, we listen to the melody!
Another “musical” toy.
If you take a piece of corrugated plastic tubing and spin it above your head, you will hear a musical sound. The more rotational speed, the higher the pitch of the sound. Experiment! I wonder what causes the sound in this case?
DO YOU KNOW?
Airplane flying from supersonic speed, overtakes the sounds it creates. These sound waves merge into one shock wave. Reaching the surface of the earth, shock wave breaks glass, destroys buildings, stuns.
The sound made by a blue whale is louder than the sound of a gunshot nearby heavy weapon, or louder than the sound of a rocket taking off.
When meteorites pass through the Earth's atmosphere, a shock wave is excited, the speed of which is one hundred times higher than sound, and a sharp sound similar to the sound of tearing material.
With a skillful blow of a whip, a powerful wave is formed along it, the speed of propagation of which at the tip of the whip can reach huge values! The result is a powerful shock wave comparable to the sound of a gunshot.
MYSTERIOUS GALLERY OF WHISPERS
Lord Rayleigh was the first to explain riddle of the gallery of whispers, located under the dome of London's St. Paul's Cathedral. Whispers can be heard very clearly in this large gallery. If, for example, your friend whispered something, turning to the wall, then you will hear him, no matter where you stand in the gallery.
Oddly enough, you hear him better the more “straight to the wall” he speaks and the closer he stands to it. Does this task simply boil down to reflection and focusing sound? To explore this, Rayleigh made a large model of the gallery. At one point he placed a decoy - a whistle, which hunters use to lure birds, at another - a sensitive flame that sensitively reacted to sound. When the sound waves from the whistle reached the flame, it began to flicker and thus served as an indicator of sound. You would probably draw the sound path as shown by the arrow in the picture. But, in order not to take this for granted, imagine that somewhere between the flame and the whistle near the gallery wall there is a narrow screen. If your assumption regarding the path of sound waves is correct, then when the whistle sounds, the flame should still flicker, since the screen would seem to be off to the side! However, in reality, when Rayleigh installed this screen, the flame stopped flickering. Somehow the screen blocked the sound. But how? After all, this is just a narrow screen and it seems to be located away from the sound path. The result gave Rayleigh the key to unraveling the secret of the gallery of whispers.
Gallery of whispers (sectional view)
Rayleigh's model of the gallery of whispers. The sound of the whistle makes the flame flicker.
If a thin screen is installed against the wall of the gallery model, the flame does not respond to the sounds of whistles. Why? Continuously reflecting from the walls of the dome, sound waves propagate in a narrow belt along the wall. If the observer stands inside this belt, he hears a whisper. Beyond this belt, further from the wall, no whisper is heard. Whisper is heard better than normal speech, since it is richer in high-frequency sounds, and the “audibility zone” for high frequencies is wider. In this case, sound propagates as if in a cylindrical waveguide and its intensity decreases with distance much more slowly than when propagating in open space.
Noisy water pipes.
Why do water pipes sometimes start to growl and moan, when do we open or close the tap? Why doesn't this happen continuously? Where exactly does the sound originate: in the water tap, in the part of the pipe adjacent directly to the tap, or in some bend somewhere further? Why does the noise only start at certain water flow levels? Finally, why can noise be eliminated by connecting to a water pipe a vertical tube, closed at the other end, containing air? As the flow speed increases, turbulence can occur at narrowing points in the pipes, which leads to cavitation (the formation and rupture of bubbles). The vibrations of the bubbles are amplified by the pipes, as well as the walls, floors, and ceilings to which the pipes are attached!. Sometimes noise can also be caused by periodic impacts of turbulent flow against obstacles (for example, narrowing) in the pipe.
Can fish talk?
Fish speak human language, only in fairy tales, but they are not deaf at all and can make sounds. They make various sounds using their teeth, air bladder, and tail. They use sounds to communicate and to scare away enemies. Fishermen know that gudgeon can squeak and bream can make gurgling sounds.
But fish also perceive sound. So predators rush to the place where there was a splash of other, small fish.
The loudest noise obtained in laboratory conditions was equal to 210 dB, or 400 thousand ac. Watts (acoustic watts), NASA reported. It was obtained by reflecting sound from a 14.63 m reinforced concrete test stand and 18.3 m deep foundation designed for testing the Saturn V rocket at the Space Flight Center. Marshall, Huntsville, Alabama, USA, in October 1965. A sound wave of such strength could drill holes in solid materials. Noise was heard within 161 km.
The energy that usually carry sound waves, very small. If a glass of water completely absorbed all the sound energy incident on it, corresponding to the volume of a fairly loud speech, and were completely thermally insulated from the environment, then it would take approximately 30 thousand years to heat the water from room temperature to boiling!
AMAZING IS NEAR!
Try this experiment and surprise your relatives!
The tool you will have is a glass (not crystal) thin-walled glass on a stem, with a capacity of half to a glass of liquid.
The glass of the glass should be clean, smooth, and not painted with anything. Having selected an instrument, begin testing its musical qualities. Before starting the experiment, wash your hands well with soap. Then, lightly wet your fingers with clean water right hand, place the glass on the table and hold it firmly by the stem with your left hand. With the middle or index finger of your right hand, start drive around along the edge of the glass.. In a few seconds you should hear melodic sound. The sound will not stop as long as you move along the edge of the glass. If this is successful, pour clean water into the glass, a little short of the edge, and continue to move your finger. You should hear a sound significantly lower than the one without water. Continuing circular movements with your finger, look at the surface of the water. Small waves formed on it. They came from those who wavered, sounding walls glasses. Now begin to gradually remove the water in small portions. The sound will gradually increase and the highest will be with an empty glass.
If you surprise me with this experience, then a “5” will appear in the magazine!
SOUND BOOM
Make a hole about 1cm in diameter in the bottom of a plastic mayonnaise bucket,
Close the bucket with a lid and place a burning candle in front of the hole. Hit the lid with your hand and the candle will go out. The sound of a candle extinguishing.
HOMEMADE SIREN
Take a wooden circle and make a holes along circles of different radii at the correct intervals. Start rotating it, placing it vertically. Direct a stream of air from the vacuum cleaner hose into the holes in each of the circles. Will the sounds be different? How to make the sound louder, higher or lower? Can you explain the working principle of the siren?
SOUNDS OF DESERT
Very often in literature there are mentions of mysterious sounds that can be heard in the desert. Today it is known that these sounds arise as a result of the movement of layers of sand, but a complete explanation of these phenomena is not yet available.
There are two types of sounding sands - "buzzing" and "whistling", which differ in frequency and duration of sound and occur under different conditions.
Whistling sounds - the slight whistling of sand underfoot can be heard on sea coasts, on the banks of rivers and lakes around the world. These are acoustic vibrations of grains of sand with a frequency from 500 to 2500 Hz.
Humming sounds - they occur deep in the desert near individual large dunes. This is a loud sound of low frequency 50-300 Hz, usually lasting from a few seconds to 15 minutes. They spread over distances of up to 10 kilometers, and are often accompanied by soil vibrations.
Sands made of quartz whistle and hum.
And here is the sound of the sands of the Hawaiian Islands reminds me of a dog barking. Hawaiian sands are the only sounding sands that are not composed of quartz.
Any phenomenon in our World has some quantitative and qualitative indicators that can be measured, and therefore changed, resulting in predictable, in most cases, consequences. And the sound was no exception to the rule!
The same parameters and indicators apply to him as to the surrounding world. The science of “Acoustics” studies these parameters and indicators.
Sound vibrations can be represented graphically as a graph of the movement of the body that generates the sound. If we are talking about a speaker that reproduces sound, then the graph will show the movement of the diffuser. If we are talking about a string, then the graph of the vibration of the string. If any wind instrument, then a graph of air vibrations inside the instrument tube, etc.
To describe such a phenomenon as sound, we must first understand what we actually hear.
- Well, firstly - volume, we distinguish between loud and quiet sounds.
- Secondly, pitch, we distinguish the sounds from which the melody is composed.
- Third, we perceive changes in the volume of individual sounds.
- Fourthly, we distinguish the sound of one instrument from another, for example, a piano from a guitar, we hear their unique timbre.
To understand how it all works, you need to imagine the whole picture.
Let's look at the graph of the diffuser's movement in dynamics.
It is worth mentioning that it cannot reproduce two sounds at the same time; it moves linearly, within certain limits.
The movement of the diffuser has an amplitude:
Roughly speaking, this is the distance by which it can deviate from a state of rest.
When it plays an audio signal, it moves within these limits:
When moving, it creates tension in the air, either compressing it or discharging it alternately. This effect of the diffuser on the air creates “sound pressure” in the air. If the strength of the signal entering the speaker increases, then the amplitude of the diffuser’s movement increases:
Following the amplitude, the speed of movement of the diffuser also increases, since it needs to travel a greater distance in the same time - the wave is the same, the amplitudes are different. Since the speed has increased, it turns out that the diffuser compresses and discharges the air faster, and if the air is compressed faster, then the pressure that arises in the air becomes greater. Accordingly, reaching our ears, the air shakes the eardrum more strongly, from this, the excitation of the nerves becomes greater and we perceive that the sound has become louder. Such are the things.
From the same example, you can notice that, despite the fact that the amplitude of the wave has increased, the time periods for both waves are the same, this is due to the “oscillation frequency”, the following parameter which we can hear. In fact, the frequency of vibration is the pitch; it is this parameter that is responsible for how we hear the sound - high or low. The higher the frequency, the higher the sound we hear; the lower the frequency, the lower the sound.
Frequency is measured in Hertz (Hz).
1 Hertz is one oscillation per second.
The hearing threshold of human hearing is from 20 to 20,000 Hz.
Each note corresponds to a certain number of vibrations. Thus, a diffuser in a speaker that plays any music pumps the air not only with a certain amplitude, affecting the volume of the audible music, but also with a certain frequency. That is, it makes either a greater or a smaller number of oscillations, depending on the melody. To at least slightly imagine the speed of movement of the speaker, we can say that the note “A” of the first octave corresponds to a frequency of 440 Hz. That is, if we hear the note “A” from the speaker for one second, then during this very second the speaker will make 440 vibrations.
The frequency of sound also affects volume, but this relates more to the “psychoacoustics” section, since it affects the issue of human perception of sound. Our hearing aids are designed in such a way that we perceive high frequencies louder than low frequencies, in terms of “sound pressure”. That is, if we take two sounds - low and high and adjust their volume so that they create the same sound pressure, then the high one will seem much louder.
The next thing we can distinguish in the sound is its ADSR envelope. The concept of ADSR refers more to single sounds and most often to the sounds of synthesizers, with digital sound synthesis. ADSR is an acronym for English words Attack, Decay, Sustaine and Release. A little later, we’ll talk about this separately in more detail, but now it’s worth briefly explaining the essence. Imagine that you took a guitar and plucked a string. First, you will hear that the sound appears very quickly, literally immediately (Attack), then the volume will decrease a little (Decrease), hold on a little (Sound) and fade away (Fade).
In most cases, ADSR refers to these stages of sound production and their settings. With digital synthesis, these parameters are set in milliseconds, and when playing the instrument, they are controlled by the performer.
Another audible quality of sound is the timbre of the instrument and our ability to distinguish these timbres from each other.
The topic is complex and will be most fully covered during our review of various tools. The timbre is affected by almost everything in the instrument, to a greater or lesser extent. The first and main thing is, of course, the method of sound production. That is, the principle of operation of the tool. On a violin, the strings are played with a bow, on a guitar, the strings are plucked, on a keyboard, the strings are struck by hammers, on a wind instrument, the strings are blown, and as a result, the sound of the instrument is born. At the same time, each instrument has its own unique sound. So, two guitars will not sound the same, something will be different in their sound, although it will still be the sound of a guitar.
This is very interesting topic, which we will examine in more detail.
Of the most obvious sound phenomena, we have considered everything; there are some that are not obvious, but we will talk about them another time.
Acoustics- the study of sounds, and sound is a wave propagating in an elastic medium. Sounds vary in pitch and volume, timbre and duration. The sounds are melodic and shrill. There are “audible” and “inaudible” sounds. All these features of sound are the subject of the study of acoustics.
Acoustics- a branch of physics that studies the processes of excitation and propagation of elastic waves in various media. But most people are accustomed to a narrower interpretation of the term “acoustics” - as the study of sounds. And the name “acoustics” itself comes from the Greek. akustikos- “auditory”.
In the ordinary sense sound- this is what the human ear perceives. In the scientific understanding, sound is the vibrations of particles that form this medium propagating in an elastic medium. The human hearing organs perceive vibrations with a frequency from 16 to 16,000 - 20,000 Hz.
Sound is a wave of elastic deformations propagating in a medium. We hear sounds because vibrating particles of the environment knock on our eardrum, and we distinguish different sounds because there is a special organ in the ear - the main membrane, different parts of which resonate at different frequencies. A person’s ability to perceive sounds—hearing—allows him to communicate with the world around him. And the finer the hearing, the richer the information that a person receives with its help.
But not only people hear sounds, but also animals, and even plants react to sounds to one degree or another. The range of frequencies that animals hear is much wider than what humans perceive. Sounds with a frequency exceeding the upper limit of the human audible range are called ultrasound, sounds with a frequency lower than the audible range - infrasound. Infrasound is well perceived by fish and whales, and ultrasound is perceived well by bats, dolphins and dogs. Sounds with frequency v~ 10 9 - 10 13 Hz are called "hypersonic". Hypersound corresponds to the highest possible frequency v max elastic waves in various media, and the maximum frequency is determined by the minimum wavelength λmin and the speed of sound v ZV:
v max =vZV / λ min.
IN solids and liquids can spread elastic waves, the length of which is not less than twice the average distance between molecules (atoms, ions). Elastic waves with a length exceeding the average free path of molecules (atoms, ions) can propagate in gases. Using the characteristic values of the speed of propagation of sound waves in various media, we can obtain the above estimates of the boundaries hypersound- for gases under normal conditions v max~ 10 9 Hz, and for liquid and solid bodies P max ~ 10 12 - 10 13 Hz. Physical limitations for the lower frequency limit infrasound does not exist, we can talk about elastic waves with arbitrarily low frequency. Material from the site
Slides: 14 Words: 463 Sounds: 0 Effects: 0Physics lesson in 9th grade. Topic: Sound waves. Objectives: 1. Introduce the concept of sound waves. Maintain a sustained interest in the subject. It's time to think seriously. Man lives in a world of sounds. Sound for humans is a source of information. Sound in the form of music, birdsong gives us pleasure. We enjoy listening to a person with a pleasant voice. Sound waves are commonly called waves perceived by the human ear. The audio frequency range is approximately 20 Hz to 20 kHz. SOUND CHARACTERISTICS Volume. Loudness depends on the amplitude of vibrations in the sound wave. The sound volume is 1B. - Sound.ppt
World of sound
Slides: 15 Words: 1517 Sounds: 0 Effects: 0"World of Sound". Introduction. The world around us can be called the world of sounds. What is sound? How do some sounds differ from others? From the history of sound. The ancient Indians mastered a high musical culture earlier than others. People have been striving to understand and study sound since time immemorial. The discovery of Pythagoras marked the beginning of the science of acoustics. What is sound? Let's look at examples that explain the physical essence of sound. The string of a musical instrument transmits its vibrations to surrounding air particles. We will hear the sound. Acoustics is the science of sound. Architectural acoustics studies the propagation of sound in rooms. - World of sound.ppt
Sound and hearing
Slides: 24 Words: 957 Sounds: 23 Effects: 0"Sound and Hearing". What is sound? Goals: 1).Develop Creative skills students. 2).Activate cognitive activity students. Topic: 9th grade, 2 lessons and an extracurricular activity. Physics. 1).What bodies are sources of sound? 2).What are the main characteristics of sound? 3).How does our hearing organ work? Causes of hearing loss. How to maintain good hearing? 4).What are ultrasounds and infrasounds? 5).Features of sound wave propagation. How, when and by whom was the speed of sound first measured? 6).Sound resonance in living nature and in musical instruments. 8).Ultrasounds and infrasounds in wildlife and technology. - Sound and hearing.ppt
Physics of sound
Slides: 11 Words: 499 Sounds: 0 Effects: 66Creative name. Sounds are our constant companions. Educational topic. Mechanical vibrations. Sound. K.Ya.Vanshenkin. Fundamental question: Why are there different sounds around us? Academic subjects: physics, biology, computer science. Project participants: 9th grade students, physics teacher. Annotation. This project covers the topic “Mechanical waves. Sound." from the physics section “Mechanical vibrations and waves. Sound." Designed for 4 hours. Working in groups helps develop communication skills. Quality problematic issues create a situation of success. The use of information and communication technologies increases interest in the subject. - Physics of sound.ppt
Sound concept
Slides: 19 Words: 1013 Sounds: 2 Effects: 19Sound sources. Mechanical waves. History of the study of sounds. The world we live in. Fork. Sound. Voice. Oscillatory movements. Find sound sources. Sound source. The saying is “dumb as a fish.” Longitudinal wave. Smile. Bell ringing. Speed of sound in various substances. Sound is a wave. What kind of device was invented for tuning musical instruments? Most insects make sound. - Concept of sound.ppt
Studying sound
Slides: 21 Words: 1004 Sounds: 2 Effects: 15Sound sources. Sound vibrations. Lesson objectives. Lesson type. During the classes. Frontal survey. History of the study of sounds. The world we live in. Fork. Sound. Vibrations of bodies generate vibrations of air. How do oscillatory movements occur? A sound source is any body that vibrates. The saying is “dumb as a fish.” Sound is a longitudinal wave. Why can't you hear the ringing of a bell inside a vessel? Speed of sound in various substances. The frequency of vibrations of the wings of insects and birds in flight. Mini test. - Study of sound.ppt
Sounds around us
Slides: 15 Words: 1483 Sounds: 0 Effects: 52Physics is all around us. Musical sounds. We listen to music willingly. The difference between music and noise. Sounds coming from vibrating strings. Musical instruments. Piano. Organ. Sounds of different instruments. Bell. The lowest musical sound audible to humans. Bottom note. Ultrasound. Infrasounds in art. The beauty of formulas. - Sounds around us.ppt
Man in the world of sounds
Slides: 30 Words: 1247 Sounds: 0 Effects: 11How diverse is the world of sounds. Content. Goals and objectives. Sounds. The ear is a sound receiver. The voice is the source of sound. Range of audible sounds. Human sound voice records. There are many cases of bird collisions with turbojet aircraft. Why do sea shells hum? "Mute as a fish." What do fish sounds like? What creates ultrasound? The bat emits short ultrasonic signals. What creates infrasound. American scientists. Does sound have color? Theoretical background. Color hearing. Measure this - I don’t know what. Trial experiment. - Man in the world of sounds.ppt
The magical world of sounds
Slides: 36 Words: 838 Sounds: 0 Effects: 2The amazing world of sounds. Sortavala, 2013. Object of study. Subject of study. Goal of the work. Research hypothesis. It is possible that sound arises from a vibrating body and is transmitted by particles of the medium. Research objectives. Research methods. Sounds. We live in a sound world. We hear sounds everywhere. We often hear on the air Hundreds of sounds of silence. In the hour of fun and separation, the beautiful world attracts us. A feeling of light, shadow, a world of coolness and warmth. A motley world of worries and worries, nature has given us as a gift. Sounds of the forest, field, sea... Every day and every hour. Sounds of joy and pain in the heart of each of us. - The magical world of sounds.ppt
“Sound” physics grade 9
Slides: 18 Words: 730 Sounds: 1 Effects: 6Sound. Frontal survey. Complete the sentences. Vibrations of particles of the medium. Independent work. Sound (sound waves). Sound sources. Origin. Fork. The ringing of a bell located inside the vessel. Pitch. Oscillation frequency. What is sound? Mini test. You have lived for many years. - “Sound” physics grade 9.ppt
Sound phenomena
Slides: 18 Words: 536 Sounds: 3 Effects: 3Sound phenomena in nature, technology and everyday life. Generalization of knowledge on the topic “Sound waves”. Biologist. Sources of sound in nature. Fly. Sources of sound in technology. Conditions for the occurrence of sound in nature. School of fish. Propagation of sound in various environments. Singing arrow. Sound and resonance. Art critic. Khomus in the world of the harp. Acoustic. Woodpecker. Informatics. Fluctuation chart. Brief interview. - Sound phenomena.ppt
Sound vibrations
Slides: 15 Words: 602 Sounds: 6 Effects: 6Studying the characteristics of sound waves using a PC. Goal: Explore various sources of sound waves using the visualization method. Sound waves. In a transparent medium - air or liquid - waves are invisible. The reason for the sound. Musical sounds and noises. Volume and pitch. The sounds we hear every day are very diverse. The first include singing, the sound of stretched strings of musical instruments, and whistling. Sound characteristics. Height - Determined by the vibration frequency, from 15 to 20,000 Hz. Volume - Depends on the amplitude of the oscillatory medium. Speed - Depends on the environment and temperature. - Sound vibrations.ppt
Oscillation frequency
Slides: 24 Words: 864 Sounds: 1 Effects: 104Creative project in physics on the topic: “Sound. Project goals. Analyze sound as a phenomenon. Explore all the properties of sound. Remember everything we know about sound. Project content: Sound sources. Sound vibrations. Pitch and timbre of sound. Sound volume. Propagation of sound. Sound waves. Sound speed. Reflection of sound. ECHO. Sound resonance. Ultrasound. Infrasound. Sound interference. Conclusion. The figure shows an elastic metal ruler secured in a vice. In this case, vibrations of the sound source are obvious. Fork. A device for measuring sound is called a tuning fork. In this case, the tuning fork is mounted on a resonator box. - Oscillation frequency.ppt
Sound vibrations
Slides: 12 Words: 711 Sounds: 0 Effects: 30Do we hear everything? How to create sound? Acoustics is a branch of physics in which sound phenomena are studied. Sound sources. Sound is created by short or long vibration of some objects. Vibrating bodies create zones of vacuum or compression near themselves. Air seals will disperse from the source in all directions. Sound is also created by a body sharply changing in volume (a balloon bursts). Sound waves are elastic waves in a medium that cause auditory sensations in humans. The emergence and perception of sound waves. Vibrations of a sound source cause waves of compression and rarefaction in the air. The ear is divided into three parts: the outer, middle and inner ear. - Sound vibrations.ppt
Sound sound vibrations
Slides: 13 Words: 520 Sounds: 0 Effects: 109Sound vibrations. Lesson plan. Repetition. Crossword. Disturbances that propagate through a medium over time. The greatest deviation of a body from its equilibrium position. Causes of sound. Sound is generated by any vibrating body. Sound sources. Natural. Artificial. Vocal cords, buzzing fly. Fork. Sound characteristics. Classification of sound waves. Infra. Audible (acoustic). Ultra. Sound. Acoustic sound. Acoustic sound is elastic waves propagating in gases, liquids and solids. The human ear perceives elastic waves with a frequency of 20 to 20,000 Hz. - Sound vibrations.pps
Sound vibrations physics
Slides: 21 Words: 892 Sounds: 0 Effects: 28Sound sources. Sound vibrations. The meaning of sound. The world around us can be called the world of sounds. With the help of speech, people communicate, with the help of hearing they receive information about the world around them. Sound is no less important for animals. Warning of danger, searching for others like you, scaring away predators, etc. (from the Greek akustikos - auditory, audible). Fluctuations with lower or higher high frequencies inaudible to the human ear. Historical reference. The first observations of acoustics were made in the 6th century BC. In the 4th century. BC. Aristotle was the first to correctly understand how sound travels through air. - Sound vibrations physics.ppt
Sound sources
Slides: 45 Words: 424 Sounds: 23 Effects: 691.Which of the following movements is a mechanical vibration? D. The movement of a ball falling to the ground. D. The movement of an athlete performing a long jump. H. Movement of the guitar string. 2. The amplitude of oscillation is... B. The deviation of an oscillating body from its equilibrium position. B. The greatest (in absolute value) deviation of an oscillating body from the equilibrium position. D. Coordinate of the oscillating body. 3. Oscillation frequency is... U. The number of oscillations per unit of time. F. The number of oscillations over some time. H. The number of oscillations in a time equal to the oscillation period. Z. Will decrease. I. First it will decrease and then it will increase. -
Sound properties
Slides: 24 Words: 706 Sounds: 8 Effects: 10Lesson topic: “sounds in nature, music, technology.” V. Mayakovsky. Lesson plan. Repetition of material about oscillations and waves. Practical task. Physical properties sound. Problem tasks: what and how are the positive and negative properties of sound manifested? Task No. 1 Using a barrel organ, explore the property of reflection of sound waves. Get the sound coming from a cymbal placed against your ear. When does sound become audible or inaudible? Task No. 3 Place the ear tubes of the stethoscope probe into your ears. Hit a metal spoon with a hammer. Achieve the sound of a “bell”. Task #4 Get a clear, musical tone using a tuning fork. - Sound properties.ppt
Sound characteristics
Slides: 17 Words: 353 Sounds: 0 Effects: 9The source of sound is... 3. In what units is the speed of a sound wave measured? 6. What is approximately the speed of sound waves in air? 7. What is approximately the most low frequency sound audible to humans? Lesson topic: “Characteristics of sound.” Sound characteristics. Sound volume Sound pitch Sound timbre. Frequency of vibrations of the wings of insects and birds in flight, Hz. Frequency range of singers' voices, Hz. Answer the questions. Why do we hear a flying mosquito, but not a bird? What characteristics does sound have? We learned that: The timbre of sound is determined by the shape of sound vibrations. - Sound characteristics.ppt
Sound and its characteristics
Slides: 24 Words: 462 Sounds: 0 Effects: 0Sound and its characteristics. What is sound? The meaning of sound. Infrasound. Ultrasound. Sound sources. Speed. Propagation of sound. Speed of sound waves. Pitch. Pure tone. Complex sound. Overtones. Sound volume. Unit of measurement. Interesting tasks. Thunder struck. Lightning. Brick. Cutter. Fly of butterfly. Low baritone. - Sound and its characteristics.ppt
Physical characteristics of sound
Slides: 21 Words: 971 Sounds: 0 Effects: 5Sound. Sound vibrations. Sound sources. Vibration of strings. Fork. Audibility of sound. Ultrasound and infrasound. Echolocation. Pitch and timbre of sound. Pure tone. Pitch of sound. Sound volume. Volume level. Precautionary measures. Propagation of sound. Sound conductors. Sound waves. Reflection of sound. Echo in the rooms. Sound resonance. Resonance and canting. - Physical characteristics of sound.ppt
Sound volume
Slides: 16 Words: 499 Sounds: 0 Effects: 3Physics lesson. “Sound and human health” 9th grade. It's time to think seriously. Sound ladder. “Every sounding body vibrates, but not every vibrating body sounds...” Our ear can only hear sounds with frequencies between 20 and 18,000 Hz. SOUND CHARACTERISTICS Volume. Loudness depends on the amplitude of vibrations in the sound wave. The sound volume is 1B. In practice, loudness is measured in decibels (dB). 1 dB = 0.1B. Pitch. - determined by the vibration frequency of the sound source. Frequency spectrum of sounds of musical instruments. Propagation of sound. Sound speed. The propagation of sound does not occur instantly, but at a finite speed. - Sound volume.ppt
Sound volume level
Slides: 8 Words: 233 Sounds: 0 Effects: 0Sound volume. Physical quantity. What does it depend on. The volume of a sound depends on: Amplitude Frequency Duration and on individual characteristics listener. Loudness in life. Harmful effects loud sounds per person. Rules. Do not listen to music at very high volumes (above 90–100 dB) for long periods of time. The person hears. Sounds. - Sound volume level.ppt
Volume and pitch
Slides: 12 Words: 303 Sounds: 3 Effects: 48Updating knowledge. What is sound? Name the causes of sound. Name the physical characteristics of sound. Mechanical vibrations of what frequencies are called sound vibrations? Volume and pitch. Sound pressure level, dB. Cello. Saxophone. Balalaika. Who flaps its wings more often in flight: a fly or a mosquito? Control test. Sound. - Volume and pitch.ppt
Pitch and timbre of sound
Slides: 18 Words: 385 Sounds: 18 Effects: 1HEIGHT AND TIMBRE OF SOUND. SOUND VOLUME (9th grade). Let's repeat and remember. Man lives in a world of sounds. What is sound? Evaluate your work. Card 1: The distance between the nearest wave crests is 3 m. The wave propagation speed is 6 m/s. What is the frequency of waves hitting the shore? Card 2: Using the oscillation graph, determine the amplitude, period and frequency of the oscillations. Demonstration of changing sound volume. Sound volume. Demonstration of pitch change. Pitch of sound. Demonstration of changing the timbre of a sound. Timbre of sound. Pitch and timbre of sound. Test "Test yourself." We will learn about the features of sound propagation in the next lesson. - Pitch and timbre of sound.ppt
Sound propagation
Slides: 13 Words: 1602 Sounds: 0 Effects: 54Sound. Introduction. Man lives in a world of sounds. What is sound? Two types of sound waves can propagate in media: longitudinal and transverse. Properties of sound. 1) Reflection 2) Refraction 3) Absorption 4) Rectilinear propagation 5) Interference 6) Diffraction. Sound conductors. Sound wave can travel a wide variety of distances. But not only air can be a conductor of sound. This means that metal conducts sound faster and better than air. Water also conducts sound well. A necessary condition for the propagation of sound waves is the presence of a material medium. Therefore, due to the lack of atmosphere, complete silence reigns on the Moon. - Sound propagation.ppt
Sound speed
Slides: 38 Words: 912 Sounds: 0 Effects: 72We are surrounded by a world of sounds: Musical instruments. Voices of the people. Traffic noise. Bird sounds. And animals. What is sound? What is the source of sound? There are both natural and artificial sources of sound. One of the artificial sources of sound is a tuning fork. List the characteristics of sound. Pitch Sound timbre Sound volume. What does the pitch of sound depend on? What determines the volume of sound? Name the units of volume and sound level. 1.The pitch of the sound depends on the vibration frequency. Frequency is measured in Hz (Hertz) 2. Loudness depends on the amplitude of vibrations in the sound wave. - Speed of sound.ppt
Speed of sound in various media
Slides: 11 Words: 368 Sounds: 0 Effects: 19How does the speed of sound depend on the medium? Our goals: Get an answer by conducting research. Write down the formula that calculates the speed of sound. Hypothesis: Experiment. Conclusion. Let's do some research. Let's put a watch in a vessel with water and place the ear at some distance. The sound is almost inaudible. Place a thick cardboard or book over the vessel at an angle. Why does sound increase? The best audibility is at an angle of inclination of the cardboard of 450. What do the reference books say? - Speed of sound in various environments.ppt
Speed of sound
Slides: 10 Words: 243 Sounds: 0 Effects: 0Propagation of sound. Sound waves. Sound speed. What does the pitch of sound depend on? What is a pure tone? What are the fundamental tone and overtones of sound? What determines the pitch of a sound? What determines the timbre of a sound? What determines the volume of sound? Name the units of volume and sound level. How does systematic exposure to loud sounds affect human health? List the characteristics of sound. Experienced confirmation. Conclusion: Availability of environment- necessary condition sound propagation. The speed of sound in air is » 330 m/s. Sound travels faster in liquids. - Sound propagation speed.ppt
“Sound propagation speed” 9th grade
Slides: 10 Words: 1261 Sounds: 0 Effects: 0Sound reflection
Slides: 9 Words: 214 Sounds: 0 Effects: 0Test on the topic “Sound. Reflection of sound." 1. What is the speed of sound in air? 2. How does the speed of sound change as the density of the medium decreases? 3. A sound wave in air is: 4. An echo is formed as a result of: 6. The action of a horn is based on the property of sound: - Reflection of sound.ppt
Reflection of sound echo
Slides: 14 Words: 1191 Sounds: 0 Effects: 8The purpose of the lesson. Study the properties of sound: reflection, echo. Practice problem solving skills. Lesson topic. "Reflection of sound. Echo. Problem solving." Nadezhda Ilyinichna Kustova, village of Ovgort, Shuryshkarsky district, Yamal-Nenets Autonomous Okrug. Tasks. a) In Yugoslavia, one of the places near Kuršumlija for a long time was considered diabolical. The columns are made of very porous stone. Reminiscent of a groan. Task. c) Goliath is the largest frog living in Cameroon (Africa). Bullfrog cry out North America can be heard several kilometers away. The male coca tree frog from Puerto Rico screams even louder. What conditions correspond to the cry of a tree frog in terms of sound pressure level? - Reflection of sound echo.ppt
Sound problems
Slides: 23 Words: 353 Sounds: 0 Effects: 0Repetition and generalization lesson in 9th grade