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Applications of Waves

Applications of Waves

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Waves may seem monotonous, but they are fascinating! They transport energy from one place to another, a characteristic that has captivated inventors and scientists for centuries. Waves' energy can be utilized to communicate over long distances or even heal the body. Waves have countless everyday uses.

The definition of waves

A wave is a disturbance that travels from one place to another in any material or medium. The particles in the medium vibrate in a predictable pattern, which can be analyzed to determine the wave's features. There are various types of waves, such as sound waves, radio waves, microwaves, water waves, and light waves. In this article, we will explore how some of these waves are used in everyday life.

Applications of wave motion

Water waves are easily recognizable and are most commonly seen in oceans and lakes. These waves have a predictable, periodic motion, but they can become destructive in the case of a tsunami. One simple application of waves involves utilizing the energy that water waves carry as they move. Tidal power is one such instance, which harnesses the power generated by the velocity of seawater flow. Tidal power stations are built in oceans to capture tides as they move in and out, and the kinetic energy of water is then converted into electrical energy. Although the amount of energy produced by tidal power is currently low, the fact that it can be done is remarkable. The given image is of a typical tidal power station located in Russia.

This image is of the Kislaya Guba tidal power station in Russia where the kinetic energy of water waves is turned into electrical energy

Applications of sound waves

Sound waves can be generated in gases, like air, but also liquids and solids. Sound waves are longitudinal waves, meaning the air particles vibrate in the same direction in which the wave is propagating.

The Ear

Sound waves are essential in daily verbal communication as they enable us to convey messages to others. When we speak, the movement of different parts of our mouth creates vibrations in the surrounding air. These vibrations propagate through the air by disturbing nearby air molecules. The sound wave continues to travel until it reaches its intended target, usually the ear of the person we are speaking to. Sound waves consist of compressions, in which air molecules are squashed closer together, and rarefactions, in which the air molecules are further apart The below illustrates areas compression and rarefaction in a typical sound wave.

A sound wave moving from source to ear. Dark areas have more vibrating air molecules (compressions) whereas lighter areas have fewer (rarefactions)

The frequency limits of the human hearing range areto. Any sound with a frequency belowor greater thancannot be detected by a human. This frequency range is known as the audible spectrum.

The speed of any wave v is given in terms of its frequency f and wavelength λ by the formula v = f λ

Sonar

Sound waves have various applications in communication, music, and other sound-related fields. Sound can travel through liquids and solids as well, with water being a better conductor of sound than air. This fact gave rise to the concept of sonar, which stands for 'sound navigation and ranging'. Sonar utilizes sound waves in water to locate underwater obstacles, such as sea mines or submarines.

At standard temperatures and pressures, sound waves travel at a speed of approximately 343 meters per second in air, but at a speed of approximately 1,484 meters per second through water.

When sound waves encounter an obstacle, such as an underwater object, they undergo a crucial property of wave motion known as reflection. The sound wave is emitted by a sender, travels outward, hits an object, reflects, and then returns to the sender. A receiver detects the reflected wave, known as an echo, and compares it to the profile of original wave to ensure that the reflection is of the same wave. The distance to the object can then be determined, as the speed of sound in water is known. The wave travels a distance of twice the distance to the object in the round trip to the object and back, in a time that can be measured. Since the speed of sound in water is constant, the distance to the object can be found using the formula: distance = (speed x time)/2.

Sonar operates on this principle, as illustrated in the diagram below. The original wave strikes the object, reflects towards the sender, and is eventually received.

The principle behind the operation of sonar. A wave is emitted by a sender and received after being reflected by the object
The principle behind the operation of sonar. A wave is emitted by a sender and received after being reflected by the object

A stationary boat floating on the surface of a lake sends out a sound wave through the water directly below it. The reflection of the sound wave is receivedseconds later. Assuming the speed of sound in water to be, calculate the depthof the lake. The speed of sound in water is constant. The sound wave travels straight down, reflects off the lake bed and returns to the boat inseconds. The depth of the lake can be calculated using the total travel time of the wave divided by two. Therefore the depth of the lakeis

Ultrasound

Ultrasound waves are commonly used in medicine, and if you have ever seen a scan of a baby in a pregnant woman, you would have seen an image that shows the features of the fetus. Ultrasound waves operate on a similar principle to that of sonar, utilizing reflection. A transducer is used to generate and receive sound waves that have a frequency hundreds of times greater than the upper limit of human hearing.

The sound waves are partially reflected at the boundaries of different tissues in the human body. Reflected waves are received by the transducer, which transforms this into a digital signal that is viewed as the image. The various tissues and body structures reflect the waves in different directions and with different amplitudes, and the result is an image of the structure of interest, such as a tissue or organ.

The image below is an example of an image produced by ultrasound, which is used in a variety of medical applications, including monitoring fetal development, diagnosing medical conditions, and guiding medical procedures.

An ultrasound image of the inferior vena cava in a human
An ultrasound image of the inferior vena cava in a human

The ultrasound waves are only partially reflected because some of the waves may be refracted, scattered or absorbed by the boundary between tissues.

Ultrasound waves of lower frequencies can penetrate to a greater depth in tissue but the detail in the resultant image is lower. Higher frequency ultrasound waves cannot penetrate as deep but provide an image with a greater resolution. We can determine the depth of the boundary between tissues beneath the skin surface, using the equation that we did for sonar, i.e., whereis the speed of the ultrasound wave, is the total time taken for the wave to be emitted and received by the transducer and the depth of the tissue boundary.

Applications of radio waves

Radio waves are a type of electromagnetic wave in the electromagnetic spectrum with the longest wavelengths, measuring approximately. Due to their ability to travel long distances, radio waves are commonly used for communication and detection. Two notable applications of waves are mobile phones and radar systems.

Although radio waves contribute to background radiation and are generally considered safe, it is still best practice to stay far from the source of radio waves. The international hazard symbol for harmful radio waves is shown in the image below, which denotes that an individual is close to a source of radio waves and should remain clear of the area.

It is important to note that while radio waves are generally considered safe, prolonged and intense exposure to them may cause negative health effects. As such, it is important to always exercise caution when in the vicinity of a potential source of harmful radio waves

Mobile phones

Radio waves are not only capable of traveling long distances but are also able to penetrate solid materials such as walls, making them ideal for carrying cellular and telephone signals. Cellular phones have built-in receivers and transmitters. Transmitters work by converting audio signals into electromagnetic radio waves, which then travel long distances and are routed and relayed via cellular stations and towers until they reach the phone of the recipient.

One significant advantage of radio waves in this application is that they travel at electromagnetic waves in free space, which is approximately299,792, meters per second, allowing communication to occur almost instantaneously with very little delay. The figure below depicts a typical cell tower, which is used to relay radio waves from the sender to the receiver. These towers are usually tall to ensure that most of the waves are not absorbed by the ground, allowing for better communication quality.

It is worth noting that while radio waves are generally considered safe, it is important to use cell phones responsibly and avoid prolonged and intense exposure to them. It is also important to ensure that cell towers are properly maintained and located in areas where they will not pose a health risk to nearby residents.

Radar

Radar, which stands for radio detection and ranging, is a system that uses electromagnetic waves to detect objects in the sky. This principle is similar to sonar, but sound waves are replaced with radio waves, as sound waves do not travel fast enough in air to be useful in detecting obstacles, such as an incoming aircraft.

Radio waves are transmitted through the air via large antennas, reflect when they strike an obstacle, and return via the same medium to the receiver. By measuring the time it takes for the radio wave to return, we can determine the distance to the object. The wave travels a total distance of 2d in the round trip to the object and back in a time t. Since the speed of electromagnetic waves in air is constant, we can find the distance d as follows:

d = ct/2

The image below shows a radar antenna capable of sending out electromagnetic radio waves and receiving the reflected waves. The size of the radar is proportional to the distance over which signals can be sent or received, allowing for long-distance communication and detection.

It is worth noting that radar has many important applications, such as in air traffic control, weather tracking, and military surveillance. However, it is also important to use radar responsibly and ensure that its use does not pose a health risk to nearby residents.

Application of light waves

As previously mentioned, light waves are electromagnetic waves that lie in the visible region of the electromagnetic spectrum. Unlike radio waves, light waves are the only type of electromagnetic waves that humans can see.

While we may take the importance of light for granted, it has numerous applications in our daily lives. For example, light waves are used in the field of medicine for diagnostic purposes, such as in X-rays and endoscopes. They are also used in the treatment of certain medical conditions, such as in photodynamic therapy for cancer.

In addition to medical applications, light waves are used in a variety of technologies, such as in fiber optic communication systems, which allow for the transmission of large amounts of data over long distances at high speeds. Light waves are also used in photography, film, and television, where they are used to capture and display images.

It is important to note that light waves also play a crucial role in our environment. They provide energy for photosynthesis in plants, which is essential for the survival of many ecosystems. Additionally, light pollution can have negative impacts on wildlife, disrupting migration patterns and breeding cycles.

In conclusion, light waves may be the only type of electromagnetic waves that humans can see, but their importance extends far beyond just vision. From medical applications to communication systems, and even the survival of ecosystems, light waves play a crucial role in our daily lives.

Flash photography

Professional photographers often carry large bags filled with equipment, including the camera flash, which is an essential piece of equipment in their toolkit. A camera flash is a device that supplies a short, intense beam of light to illuminate the scene for a photograph to be taken. By providing additional light, the flash can improve the quality of the image, making it clearer and more defined.

The flash emits a short burst of white light, which is intense enough to brighten the image and reduce the effects of shadows or low light conditions. This is particularly important in situations where natural light is insufficient, such as indoor or nighttime photography.

In addition to photography, the application of light waves extends to many other areas. For example, light waves are used in medical imaging technologies, such as X-rays, CT scans, and MRI scans. They are also used in laser surgery, where a concentrated beam of light is used to remove or reshape tissue.

Light waves are also used in telecommunications, such as in fiber optic communication systems, which use pulses of light to transmit data over long distances at high speeds. They are also used in electronic displays, such as computer monitors and televisions, where they are used to produce images.

In conclusion, the camera flash is just one example of the many applications of light waves in our daily lives. From photography to medical imaging, telecommunications to electronic displays, light waves play a crucial role in a wide range of technologies and applications.

This image shows a bright white flash that is generated by a modern digital camera
This image shows a bright white flash that is generated by a modern digital camera

Applications of Waves - Key takeaways

Sound waves are created by the vibrations of air molecules and can travel through different mediums at varying speeds. For example, sound travels faster through water (∼1500 m/s) than it does through air (∼343 m/s). This makes sonar an ideal technology for underwater detection, as it can travel greater distances and provide accurate imaging.

Sonar works by emitting sound waves and analyzing the reflected waves that bounce back. The speed of sound in water is used to calculate the distance to an underwater object by measuring the total time taken for the wave to be emitted, reflected, and received.

Ultrasound is another technology that uses the wave property of reflection, similar to sonar. In ultrasound imaging, a transducer is used to generate and receive the wave. The frequency of ultrasound waves is much higher than the upper-frequency limit of human hearing. Ultrasound waves are partially reflected by the boundary between, allowing for the creation of images of internal organs and tissues.

Radio waves are electromagnetic waves with large wavelengths that can travel long distances through air and penetrate solid materials. Mobile phone signals are transmitted via radio waves, routed through cellular stations, and received by other mobile phones.

Radar is another technology that uses the wave property of reflection of electromagnetic waves. It is used to detect objects and obstacles in the air, such as planes and missiles. By the reflected waves, radar can provide information about the location, speed, and direction of the object.

In conclusion, the wave properties of reflection and penetration are utilized in a variety of technologies, from sonar and ultrasound imaging to radio waves and radar. These technologies have revolutionized the way we communicate, explore, and understand our world.

Applications of Waves

How are waves applied in wireless communication?

Sound waves can be used for everyday verbal communication. Radio waves can be used for radio and mobile phone communication. 

How are waves applied in motion?

Light sails can be used to propel spacecraft by using the pressure of light waves exerted on large solar sails.

What are the applications of light waves?

Light waves can be used for illumination and lighting for photography. Certain wavelengths of laser light can also be used for medical diagnostic purposes.

What are the applications of waves in vehicles? 

Light waves are used in car headlamps to illuminate the road surface ahead of the car. Ships and boats may use stronger lamps to illuminate and navigate through the darkness. Radar technology is used in modern cars to detect obstacles outside the illumination of the headlights.

How do you calculate the speed of a wave? 

The speed v of a wave in terms of its frequency f and its wavelength λ is given by v = f × λ

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