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R. Meaning/process and importance of LASER applications

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R. Meaning/process and importance of LASER applications

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What is a LASER?

Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. Laser is a source of light but it is different from other light sources. It is an optical device that makes a high intensity and extremely directional beam which has a narrow frequency range. Lasers are more used as a strong electromagnetic beam than a light beam.

What process occurs in a Laser Application?

A laser is created when the electrons in atoms in special glasses, crystals, or gases absorb energy from an electrical current or another laser and become “excited.” The excited electrons move from a lower-energy orbit to a higher-energy orbit around the atom’s nucleus. When they return to their normal or “ground” state, the electrons emit photons (particles of light).

These photons are all at the same wavelength and are “coherent,” (related to, uniform, united, consistent) meaning the crests and troughs of the light waves are all in lockstep. In contrast, ordinary visible light comprises multiple wavelengths and is not coherent.

Laser light is different from normal light in other ways as well. First, its light contains only one wavelength (one specific color). The particular wavelength of light is determined by the amount of energy released when the excited electron drops to a lower orbit. Second, laser light is directional. Whereas a laser generates a very tight beam, a flashlight produces light that is diffuse. Because laser light is coherent, it stays focused for vast distances, even to the moon and back.

What is the importance of Laser Application?

Lasers are used in optical disk drives, laser printers, barcode scanners, DNA sequencing instruments, fiber-optic, semiconducting chip manufacturing (photolithography), and free-space optical communication, laser surgery and skin treatments, cutting and welding materials, military and law enforcement devices for marking targets and measuring range and speed, and in laser lighting displays for entertainment. They have been used for car headlamps on luxury cars, by using a blue laser and a phosphor to produce highly directional white light.

All in all, used for medical, law-enforcing, technological and weaponry purposes.

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P. What are the purposes and benefits of sounds aside from hearing?

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P. What are the purposes and benefits of sounds aside from hearing?

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Sound surrounds us, passing across the world in waves. These waves arise as a result of atoms that vibrate and interfere with each other. These vibrations come from the source and pass through the atmosphere—vibrations that produce waves of energy. Humans and other animals use these sound waves not only to communicate, but also to perform a variety of tasks.

COMMUNICATIONS

Without sound signals waves, human beings will not be able to speak verbally. Your vocal cords produce sound waves, which are then distributed through the air to the ears of the listeners. Current communication systems, such as radios and televisions, use the same fundamental principle to relay sound to your ears.

EXPLORATION OF OCEANS

Scientists use sound waves in sonar devices to study the oceans. Sonar sends out sound waves, which then echo back to the source as the object is struck. Scientists may use this echo to assess the scale and position of the entity that echoed back on the sound waves. Navy boats are now using sonar equipment to hunt for enemy submarines.

RESOURCES FROM UNDERGROUND

Geologists use sound waves to search for minerals such as oil underneath the ground. They bounce sound waves through the ground and calculate the direction they move across the earth. By analyzing the way the sound waves move across the earth, geologists may draw inferences about the composition and make-up of the earth. Geologists may also use the waves generated by earthquakes to study the land in a similar way, as well as to study the impact and strength of the earthquakes themselves.

HUNTING

Many animals or creatures are using sound waves to search for food.In specific, bats use the form of a sonar to hunt for prey. The Bats project sound waves that bounce off the prey. When the sound waves return to the bats, they may assess their distance from their prey. In this way, even if the eyesight is relatively low, bats can search successfully at night. Some marine mammals / sea creatures, such as dolphins, and whales use similar modes of echolocation to search for prey and to communicate with each other.

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O. Identify and discuss sounds' different characteristics

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O. Identify and discuss sounds' different characteristics

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Sound is a form of energy. It is produced by the vibration of the body. It requires a material medium for its propagation and can be transmitted through solids, liquids and gases. When sound is conveyed from one medium to another medium there is no bodily motion of the medium. It requires a definite interval of time to travel from one point to another point in a medium and its velocity is smaller than the velocity of the light. Velocity of sound is maximum is solids, which have higher bulk modulus and least in gases. Sound may be reflected, refracted, or scattered. It exhibits diffraction and interference.In transverse mode it exhibits polarization also.

PITCH/FREQUENCY

It is the characteristic of sound which is the sensation conveyed to our brain by the sound waves falling in our ears. It depends directly on the frequency of the incident soundwaves. Though the pitch is directly related to frequency, they are not the same; in general the frequency is a physical quantity whereas the pitch is a physiological quantity.

QUALITY/TIMBRE

The quality of the sound is the one which helps us to distinguish between the musical.It is the characteristic which enables us to distinguish between the sounds produced by different sources, the more pleasant sound is said to be of rich quality.

INTENSITY/LOUDNESS

Loudness of a sound depends on the amplitude of the vibration producing that sound. Greater is the amplitude of vibration, louder is the sound produced by it. The loudness of a sound also depends on the quantity of air that is made to vibrate.Suppose when we pluck a string of the sitar it starts vibrating with low amplitude and if we apply more energy by plucking more strongly, the string will vibrate with the greater amplitude and produce a loud sound. As the amplitude of vibration increases, sound also increases.Loudness of sound is measured in decibel (dB) units.

Sound has different features.

The sound we hear is a source of energy created by vibrations that move through the air or some other medium and are audible when they enter a person's ear. As a result, sound assists us in communicating with others. We may compare the properties of sound to the properties of a wave since sound is a wave.

We immediately note certain fundamental characteristics when sound waves are expressed in a waveform. The waveform is a visual representation of the vibration difference in the air that allows sound to fly. This waves alternate between high and low pressure zones. Sound waves now resemble light and other electromagnetic radiation thanks to the waveform.

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N. How does a human ear receive and detect sounds?

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N. How does a human ear receive and detect sounds?

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1.Sound transfers into the ear canal and causes the eardrum to move

2.The eardrum will vibrate with vibrates with the different sounds

3.These sound vibrations make their way through the ossicles to the cochlea

4.Sound vibrations make the fluid in the cochlea travel like ocean waves

5.Movement of fluid in turn makes the hair cells The auditory nerve picks up any neural signals created by the hair cells. Hair cells at one end of the cochlea transfer low pitch sound information and hair cells at the opposite end transfer high pitch sound information.

6.The auditory nerve moves signals to the brain where they are then translated into recognizable and meaningful sounds. It is the brain that “hears”.

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Video about Hearing and How it Works | MED-EL

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M. What is the frequency of the second hand of a clock?The minute hand?The hour hand?

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M. What is the frequency of the second hand of a clock?The minute hand?The hour hand?

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The frequency for second hand is 60 s, 0.0166 Hz.

The frequency for minute hand is 3600 s and

While the frequency for hour hand is 43200 s and

The time period and frequency relation is given as

f=1/T

Here, T is the time period and f is the frequency.

Now the time period for the second hand is = 1 min = 60 s.

So frequency,

f=1/60s
f=0.0166 Hz

Time period of minute hand = 1 hour = 3600 s.

so frequency,
f=1/3600s

f=2.77x10^-4 Hz

Time period of hour hand = 12 hour = 43200 s.

so frequency,
f=1/43200s
f=2.3x10^-5 Hz

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Estrella,Raychelyn liezel N.-GROUP 2 NARRA

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K. Different Regions of electromagnetic spectrum; their properties(wavelengths & frequencies) and functions(energies/applications)

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K. Different Regions of electromagnetic spectrum; their properties(wavelengths & frequencies) and functions(energies/applications)

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The Electromagnetic Spectrum's Regions and Their Applications

The electromagnetic (EM)spectrum is a continuous continuum of electromagnetic waves that

are grouped in frequency or wavelength order. It is divided into regions based on a specific wavelength interval frequency. The names given to these regions are solely for the purpose of finding the wave's location in the spectrum.

There is no simple difference between one wave form and the other.RADIO WAVES

The longest electromagnetic waves are radio waves.

Discovered by: Heinrich Hertz in 1887.

Wavelength: ranging from 10^-1 m to 10^4 m.

Frequency: ranges from 30 kHz to 3000 MHz. For wireless technology, this frequency range is split into bands.

Functions: The word "radar" stands for "radio tracking and ranging." It uses radio waves for object identification, weather forecasts, military intelligence, and air traffic control, as well as highway patrol speed monitoring and satellite and debris tracking.

Applications: Radio waves are used in applications such as automatic gate, Wi-Fi, and Bluetooth. Other radio wave technologies that have revolutionized today's technology include global positioning systems (GPS) and radio frequency identification (RFID). The universal product code (UPC) or bar code that we see on certain grocery products is very similar to RFID. It has the ability to store and transfer data. One common example of RFID is the easy tag which we use to pay the toll in our expressways.

Produced by: An alternating current (AC) circuit connected to an antenna produces the sound. Electronic instruments such as LC oscillators, which are electrical circuits made up of inductors (L) and capacitors (C) that are used to generate and pick up signals at a certain frequency, emit radio waves. Extraterrestrial sources of electromagnetic waves include the sun and Jupiter.

MICROWAVES

Discovered by: James Clerk Maxwell in 1864.

Wavelength: 10m to 10-m

Frequency: 300 MHz to 300 GHz

Functions: Microwaves are high-frequency radio waves that are primarily used for communication, particularly between the frequencies of 2 and 40 GHz. Prior to the invention of optical fibers, they were mostly used for long-distance telephone calls. Signals for cable tv, as well as visual or audio streams from processing vans to radio stations, are sent by them. In remote sensing, microwaves are used.

Applications:Microwave ovens are a popular kitchen item. It cooks food by transmitting energy to the water molecules in the food using 2.45 GHz microwaves. Microwaves are used in manufacturing processes for drying and curing materials in addition to heating surplus food. In the medical sector, microwaves are commonly used. The heat of microwaves is used to shrink or dissolve tumors in microwave ablation.

INFRARED WAVES

The term "infrared" simply translates to "behind red."

Discovered by: Sir William Herschel, a British astronomer, in 1800.

Wavelength: 7.5x10^-7 m to 10^-3 m

Frequency: Infrared radiations (IR) have a lower frequency than the red part of the visible light. Their frequencies range from 3x10^11 Hz to 4x10^14 Hz

Functions:Remote controls for television sets, burglar detection devices, night vision monitors, and some types of thermometers all use infrared rays. Infrared data association ports are present on most computers, notebooks, palmtops, and printers, enabling us to upload and print data without using a wire. Infrared radiation can also be used to prepare food.

Applications:Heat Lamps are used by physiotherapists to treat sports injuries. Oncology, rheumatology, physical therapy, and orthopedics all use highly advanced medical technology for prediction and diagnosis. It's also used to monitor treatment and recovery progress.

Produced by: Infrared radiation is invisible to the naked eye, but it is felt as fire. Infrared radiation is produced by humans, locations, objects, and animals in proportion to their temperature. Infrared beams are shorter at higher temperatures.

GAMMA RAYS

Radioactive elements such as cobalt-60 and cesium-137 release gamma rays. Gamma rays are produced from astronomical objects such as the sun, interstellar clouds, and supernova remnants. Because of their short wavelengths, gamma rays are very penetrating.

Discovered by: Paul Villard, a French chemist, and physicist in 1900.

Wavelength: ranging from less than 10^-14 m to 10^-10 m

Frequency: greater than 10^19 Hz

Functions:In the industrial world, gamma rays are used to detect metal cracks and to sterilize appliances and commercial goods. Non-contact industrial sensors with gamma sources are used to monitor volume sizes, density, and thickness in the refining, processing, chemical, food, soaps, and detergents, as well as the pulp and paper industries. Bacteria, flies, and fungi are all killed as food is irradiated with gamma rays.

Applications: In the course of radiotherapy, gamma rays are used to destroy cancer cells. It is likely that the operation may be external or internal. The patient is subjected to a pulse of radiation during external radiotherapy. Examples include gamma knife surgery and stereotactic radiotherapy. Radiation from implants or liquids mounted within the body is used in internal radiotherapy. This is referred to as brachytherapy.

VISIBLE LIGHT

Visible light, or merely light, is the name for this portion of the electromagnetic spectrum. The acronym ROYGBIV (red, orange, yellow, green, blue, violet) can be used to note the order of visible light colors from longest to shortest. Red, violet, violet, violet, violet, violet, violet, violet, violet, violet, violet, violet, violet, violet, violet Indio is no longer considered a distinct color in current use.

Discovered by: Isaac Newton in 17th Century.

Wavelength: 4x10^-7 m to 8x10^-7 m are the only ones seen by our naked eye.

Frequency: 4x10^14 Hz to 8x10^14  Hz

Functions: The use of light-emitting diodes in visible light communication (VLC) is an evolving method of wireless communication technology that allows for simultaneous audio and video streaming. Optical fibers, which have replaced telephone lines, relay signals at high speeds and/or over long distances using visible light.

Applications: In our daily lives, visible light serves a variety of purposes. It assists in the interpretation of objects. It's also used in street lights, billboards, car headlights, and taillights. Visual light is used for a computer with a viewable mirror. Examples include televisions, liquid crystal screens, and touchpad computers. Plants use visible light for photosynthesis as well..

X-RAYS

Roentgen rays are another name for X-rays. In most cases, the letter X is used to denote an unknown quantity. Since he didn't know the existence or sources of the rays he discovered, Roentgen named them X-rays. For his unintentional observation of X-rays, he received the Nobel Prize in Physics in 1901. Soft X-rays are capable of penetrating soft surfaces such as skin and bones. Soft X-rays are less penetrating than hard X-rays.

Discovered by: German physicist Wilhelm Conrad Roentgen

Wavelength: 10^-12 m to 10^-8 m

Frequency: 3x10^19 to 3x10^16 Hz

Functions: The sun and other stars give off X-rays. They can also be formed when accelerated electrons interfere with metal or medical equipment. m X-rays are used to diagnose skeletal anomalies such as fractures and tumors. In addition, they are used in dental imaging.

Applications: X-rays are used in airport security screening to see the interior of passenger bags, in addition to capturing photos of our internal body parts, as in computer axial tomography (CAT). They are also used in the diffraction method to research the structure of atoms in a crystal.

ULTRAVIOLET RADIATION

UV (ultraviolet radiation) is a popular abbreviation for ultraviolet radiation. UVA, UVB, and UVC are the three forms of ultraviolet light. UVC is absorbed nearly entirely by the atmosphere and never touches the Earth's surface. The ozone in the soil filters UVB. UVA is responsible for 95% of the solar UV that enters the Earth.

Discovered by: German physicist Johann Wilhelm Ritter

Wavelength: ranging from 6x10^-10 m to 4x10^-7 m ;

UVA = 315 nm to 400 nm , UVB =  280 nm to 314 nm, UVC = 60 nm to 279 nm

Frequency: 8x10^14 Hz to 10^17 Hz

Functions: The light is a big source of ultraviolet rays. UV rays are often emitted from special lamps. To detect forged bank notes, UV lights, also known as black light, are used. The security marker ink that we use for our signatures in our bankbook is clear under black light. It is used in forensic examinations at crime scenes, in techniques such as looking for signs of blood and other bodily fluids, and in finger print research.

Applications:Hospital equipment is sterilized with black light, and water is purified with it. It's also used in pest-control and fly-trap systems, as well as in theaters to create the "glow in the dark" effect. UVA is used to treat skin diseases that induce depigmentation of areas of the skin, such as psoriasis and vitiligo. Vitamin D is produced in our bodies as a result of exposure to ultraviolet light.

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J. Total Internal Reflection:Definition, property,principal behind and practical usage

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J. Total Internal Reflection:Definition, property,principal behind and practical usage

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Definition: Total inner reflection, in physics, total reflection of a ray of light inside a medium such as water or glass from the surrounding surfaces back into the medium. The wonder happens if the angle of incidence is greater than a certain restricting angle, called the critical angle. Total internal reflection of light is used in many optical instruments like binoculars,  microscope, periscope, telescopes etc. Optical fibre works on the principle of total internal reflection. The brilliance of a precious stone is due to total inner reflection.

The phenomenon of total internal reflection occurs as a beam of light passes from one medium to another with no lack of color. When the angle of incidence is higher than the critical angle, this happens. The refractive index, wavelength of light, and temperature of the medium all influence the critical angle of a medium.

Only if and only if the following conditions are fulfilled does absolute internal reflection occur:

1)The light ray travels from a denser to a denser medium.

2)The critical angle must be greater than the incidence angle.

The equations/formulas below are related to complete internal reflection:

This is where Snell's law comes into play. Light bends or refracts as it flows from one source to another. Since the speed of light is constant, the distance traveled by light within a medium is determined by the density of the medium. You can estimate the ray's refracting path and angle using this rule. The law of refraction, also known as Snell's Law, was named after Willebrord Snell.

A diamond's radiance is due to total internal reflection. When the incident ray strikes each face of the diamond in such a way that the angle created exceeds the critical angle. A diamond-to-air surface has a critical angle of just 24.4o. As a result of its narrow critical angle with sunlight, light cannot effectively escape a diamond.

Facets on diamonds are designed to make this impossible by allowing light to escape only in certain directions. Good diamonds have a lot of internal reflections, so light is centered on the few areas where it can escape. Mirages, optical fibers, corner reflectors, periscopes, and binoculars are other examples of absolute internal reflections.

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I. Wave properties;benefits and applications

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I. Wave properties;benefits and applications

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FREQUENCY -  is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. It's also a measure of how many waves pass a point in a certain amount of time.

AMPLITUDE - amplitude modulation, AM is used for audio broadcasting on the long medium and short wave bands, and for two way radio communication at VHF for aircraft.

WAVELENGTH - The energy of a wave is directly proportional to its frequency but inversely proportional to its wavelength. That means the greater the energy, the larger the frequency and the shorter the wavelength. Given the relationship between wavelength and frequency, short wavelengths are more energetic than long wavelengths.

SPEED -  It is important to know the speed of a wave, because this is the speed at which the energy it carries is transferred from one place to another. Speed is a measure of how fast something is.

-A wave's duration is the amount of time it takes for a particle on a medium to complete one complete vibrational loop. A period is a unit of time that is measured in seconds, hours, days, or years. For example, it aids us in determining the Earth's orbital time around the Sun, which is nearly 365 days; the Earth completes a rotation in 365 days.

(2) Wave Properties; benefits and applications

Frequency (pitch)

Pitch can only be determined if the sound has a pitch that is clear and consistent enough to distinguish it from the noise.Since pitch is largely depends on the perception of the listener, it is not an objective physical property of sound.Pitch is the consistency that helps one to judge sounds as "higher" and "lower."It offers a tool for arranging sounds on a frequency-based scale.Pitch may be viewed as a music expression for frequency, but not quite the same.High-pitched sound allows molecules to oscillate fast, while low-pitched sound causes slower amplitude.

Amplitude (dynamics)

The amplitude of the sound wave decides its relative loudness.Studies have found that people interpret sounds at extremely low and very high frequencies to be softer than those at mid-frequency, even though they have the same amplitude.In music, the sound of a note is called its dynamic level.In physics, they calculate the amplitude of sound waves in decibels (dB) which does not fit with dynamic levels.Higher amplitudes correspond to louder sounds, whereas shorter amplitudes correspond to quieter sounds.

Timber (tone color)

Timbre refers to the colour of the tone, or the "feel" of the voice.Sounds with different timbres create different wave shapes that influence our sound perception.In physics, this is referred to as the timbre of a wave.It's what makes it possible for people to easily distinguish sounds (e.g. cat's meow, running water).The sound created by the piano has a distinct color hue from the sound produced by the guitar.

Duration (time/rhythm)

In music, duration is the amount of time the pitch or tone lasts.They can be described as long, short, or time-consuming.The length of a note or tone determines the timbre and rhythm of a sound.A classical piano piece appears to have notes longer in length than the notes played by a keyboard player at a pop concert.In physics, the duration of a sound or a tone starts when the sound registers and stops after it cannot be detected.
https://drive.google.com/file/d/1gR5dUjYGxbbjooX0ywzhRUF_qleoyY9Y/view?usp=sharing

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H. Wave properties;defenition and examples

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H. Wave properties;defenition and examples

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Wave properties are elements we can measure for any wave. The basic properties (parts) of a wave include: frequency, amplitude, wavelength and speed.

Frequency is a measure of how many waves pass a fixed point in a given amount of time. For example, an “A” note on a violin string vibrates at about 440 Hz (440 vibrations per second)-The greater the amount, the closer the waves are together and the more energy the waves can bring. The frequency unit is Hertz (Hz), which is single wave per second.

Amplitude, in physics, is the maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position. For example, when looking at a sound wave, the amplitude will measure the loudness of the sound therefore, sounds with greater amplitude will be louder and light with greater amplitude will be brighter.-The level of the wave, or the difference across lines across the crest or trough, is called amplitude. It is proportional to the amount of energy transported by the wave. Sounds with more amplitude are quieter, and lights with more amplitude are lighter.

Wavelength can be defined as the distance between two successive crests or troughs of a wave. This means shorter wavelengths are influenced by the frequency; a higher frequency causes shorter wavelength and greater energy.-The difference between the crests of one wave and the crests of the next wave is measured in wavelength. A shorter wavelength and more energy are generated by a higher frequency.

Speed, in the case of a wave, is the distance a wave travels in an amount of time. The speed of a wave is determined by the type of wave and the nature of the medium. If the medium is uniform (does not change), then the wave speed will be constant. For example, the speed of sound in dry air at 20C is 344 m/s but this speed can change if the temperature changes.-The time it takes for a particle on a medium to complete one complete vibrational loop is known as the duration of a wave. Duratio

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-electromagnetic radiation refers to the waves of the electromagnetic field, propagating through space, carrying electromagnetic radiant energy. It includes radio waves, microwaves, infrared, light, ultraviolet, X-rays, and gamma rays

-Waves of the transmitter (Instant Communication)

Waves of Infrared Light (Invisible Heat)

Rays of Visible Light (Colors of the Rainbow)

Waves of Ultraviolet (Energetic Light)

X-rays are a form of radiation (Penetrating Radiation)

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C. Types of waves according to the usage of material/medium

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C. Types of waves according to the usage of material/medium

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Mechanical Waves- Mechanical waves require a medium in order to transport their energy from one location to another. A sound wave is an example of a mechanical wave. Sound waves are incapable of traveling through a vacuum.

Examples of Mechanical Waves are water waves, seismic waves, and sound waves.

-A form of wave in which matter oscillates and energy is transferred through a medium. The transmitting medium limits the distance that waves can travel. The oscillating materials rotate around a central axis.

Mechanical waves may only occur in the presence of a medium. If there is no medium, waves cannot transmit.

Electromagnetic Waves- Electromagnetic waves are produced by the vibration of charged particles. Electromagnetic waves that are produced on the sun subsequently travel to Earth through the vacuum of outer space. Were it not for the ability of electromagnetic waves to travel to through a vacuum, there would undoubtedly be no life on Earth.

Examples of Electromagnetic Waves are microwaves, radio waves, x rays and visible lights.

-Since it is generated by the vibration of charged particles, it is capable of transmitting waves across empty space.

WHAT IS MECHANICAL WAVES AND ELECTROMAGNETIC WAVES:
https://youtu.be/96XMFM0Rcg4

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B. Types of wave according to propagation

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B. Types of wave according to propagation

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Ground Waves - are electromagnetic waves refer to propagation of radio waves parallel to and adjacent to the surface of the Earth, following the curvature of the Earth. Energy is lost in propagation of radio waves and attenuated as it passes over the surface.

EXAMPLE: AM Radio- It's an excellent demonstration of ground waves. AM radio stations are using ground waves to protect their listening areas. As distance attenuation reduces as the frequency decreases, significantly lower frequency (VLF) and extremely low frequency (ELF) ground waves can be used to communicate globally.

Sky Waves (Ionospheric Waves) -  energy radiated by an antenna, that is a sky wave, would be wasted energy as far as radio communication is concerned if it is continued on its path and did not return to earth but under certain conditions it is reflected from the ionosphere. Sky waves may undergo reflection and refraction or both.

EXAMPLE: The frequency and wavelength of an electromagnetic wave are related by the equation: c =  x f

where f is the frequency of the wave, c is the speed of light, and  is the wavelength in meters.

It occurs when the signal from the Earth-based antenna is transported back to Earth from the ionized surface of the upper atmosphere (ionosphere). Signal refraction is responsible for this effect. The sensor of a sky wave will bounce back and forth between the ionosphere and the surface of the earth over a number of hops. The signal can be picked up thousands of kilometers away from the transmitter using this propagation method.

Space Waves - these waves have the ability to propagate through the atmosphere, from transmitter antenna to receiver antenna. These waves can travel directly or can travel after reflecting from earth’s surface to the troposphere surface of earth. So, it is also called as Troposphrical Propagation.

EXAMPLE: Microwave linking

Broadcast Fading Zone - an appreciable portion of Ionospheric wave is returned to earth during night time which extends the service area of the station well beyond that covered by surface wave. Due to these fluctuations in the ionosphere, fluctuation also produced in reflected waves relative to surface waves resulting in severe fading of combined waves.

EXAMPLE: the experience of stopping at a traffic light and hearing an FM broadcast degenerate into static, while the signal is re-acquired if the vehicle moves only a fraction of a meter.

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Some of the most common examples of mechanical waves are

Water waves - In fluid dynamics, dispersion of water waves generally refers to frequency dispersion, which means that waves of different wavelengths travel at different phase speeds. Water waves, in this context, are waves propagating on the water surface, with gravity and surface tension as the restoring forces

Sound waves - Sound is a mechanical wave that results from the back and forth vibration of the particles of the medium through which the sound wave is moving. If a sound wave is moving from left to right through air, then particles of air will be displaced both rightward and leftward as the energy of the sound wave passes through it. The motion of the particles is parallel (and anti-parallel) to the direction of the energy transport. This is what characterizes sound waves in air as longitudinal waves.

Seismic waves - Seismic waves are waves of energy that travel through Earth's layers, and are a result of earthquakes, volcanic eruptions, magma movement, large landslides and large man-made explosions that give out low-frequency acoustic energy.

Ropes and Spring

Tsunami Waves

Air

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E. Parts and Examples  of Longitudinal Waves

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E. Parts and Examples  of Longitudinal Waves

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Longitudinal Waves are waves whose vibration is parallel to the wave's points located.

Parts of Longitudinal waves:
Compression: would happen when the atoms are pressed close together;what happens if the atoms are squeezed together closely

Refraction: is when the atoms are not pressed together, they're spread out; is when atoms are not packed together and instead scattered out.
Wavelength: The gap between two crests or troughs

Some examples:

1. The tsunami waves

2. Vibrating Tuning Fork

3. Windows Shake When Thunder Strikes Nearby

4. Acoustic Microscopy

5. Sonic Weapons

6. P wave or compressional wave are two types of seismic waves.

7. Ultrasound

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D. Parts and Examples of Transverse Waves

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D. Parts and Examples of Transverse Waves

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*Crest-is the top of the wave. The wave has reached its full height.
Trough

Pah- is at the bottom of the wave. -The wave has reached its lowest point.

Wavelength-is the length of the wave-The length of a wave is measured from crest to crest or trough to trough.
Amplitude-is the highest amount of vibration that the medium gives from the rest position

The vertical distance between the center line and a peak or the center line and a trough is called AMPLITUDE, and it should usually be the same. It has something to do with the wave's force.
Rest Position- is the position where a wave would be if there was no movement.

Examples of Transverse waves:

Light, infrared, ultraviolet, radio waves, microwaves, Waves on the water's surface cause the water's surface to rise and fall, Electromagnetic waves of all forms, including visible light, radio waves, and ultraviolet waves.

x-rays, and gamma rays

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1. Wave

- A wave can be described as a disturbance that travels through a medium from one location to another location. Wave moves only energy, and does not move matter.

-a disturbance or variability in a medium that transfers energy from point to point and can come in the form of an elastic deformation, a change in pressure, electrical or magnetic intensity, electrical potential or temperature.

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Q. Differentiate Acoustics from Optics. Provide the areas of their studies underlying. 

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Q. Differentiate Acoustics from Optics. Provide the areas of their studies underlying. 

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Phonons play an important part in thermal and electrical transport properties of crystals. Phonons are characterized as the quantity of lattice vibrations present in crystals. They are bosonic in nature, interacting with electrons found in crystals, and thus regulating the transport properties of crystals. Phonons are categorized as acoustic and optical divisions.

The former one passes at the speed of sound, while the latter communicates with the external electromagnetic fields applied. The following are few differences usually encountered between acoustic and optical phonons.

Acoustic phonons:

1. These are the lattice waves that occur due to in phase displacement of atoms present in the lattice of the crystal. They usually travel with sound velocity.

2. At long wavelengths the dispersion relation corresponding to these phonons is almost linear in nature.

3. In longitudinal acoustic (LA) mode the atoms move in phase along the direction of propagation of waves. In contrast, the atoms move perpendicular to the direction of motion of waves in transverse acoustic (TA) mode.

4. TA phonons often exhibit negative frequencies near the phase transformation point of a solid, and the phenomenon is called dynamical instability.

5. These phonons usually converge to zero at the center of the Brillouin Zone.

Optical phonons:

1. These are observed for the crystals containing multiple atoms as basis such as NaCl, GaAs, ZnO etc.

2. These lattice waves occur due to the opposite displacement of atoms present in a basis of crystals. For example, the cation and anions present in NaCl move opposite to each other. The opposite displacement of cation and anions results in a change in the dipole momentum due to charge separation of atoms. The dipoles can interact with the externally applied electromagnetic waves and hence the name optical phonons.

3. Optical phonons exhibit non-zero frequency at the Brillouin Zone center.

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L. Create a Venn Diagram for the similarities and differences of Sounds and Light

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L. Create a Venn Diagram for the similarities and differences of Sounds and Light