Introduction to Waves
Waves are an integral part of our daily lives as well as physics. Scientists conduct several experiments on the basis of the properties of waves. The waves include several factors like their amplitude, wavelength, speed, etc.
One can learn how to analyse different factors of the wave through analysis of their amplitude, wavelength and speed. Such factors determine the difference between several waves and hence make them unique. Some of such waves can help in the distribution of light and sound to different places.
Hence, Let us learn about each of its factors in detail and understand its properties and factors affecting the amplitude of the wave.
Wave Definition and How to Graph it?
A wave is a disturbance that travels from one point to another in a medium. Waves can travel in air and water but they do not exist in a vacuum. There are properties shown by a wave-like wave amplitude, speed, frequency, wavelength, phase of a wave, and period.
When we draw a wave on the graph, we draw it travelling through time or distance. The Y or the vertical axis shows the amplitude of a wave while the X or the horizontal axis shows the time or distance through which the wave travelled.
Amplitude of a Wave
Characteristics of Wave
The highest point of the wave is called the crest while the lowest point of the wave is called a trough.
The line which is passing through the centre of the wave shows the resting position of the medium when no waves might be passing through it.
The Amplitude of A Wave
The amplitude of a wave can be described as the measure of the displacement of the wave from its resting position. The amplitude can be calculated by observing the graph of a wave and measuring its height from the resting position.
The strength and intensity of a wave are measured through the wave. Similarly, the loudness of sound is measured by the amplitude of a sound wave. Also, the energy of the wave is considered directly proportional to the amplitude of the wave.
Wave
The Wavelength of A Wave
Distance between two corresponding points on continuous cycles of a wave is considered to be the wavelength of a wave. The wavelength can be measured through two crests or two troughs of the wave.
The Greek letter Lambda (𝛌) is used to denote the wavelength of a wave in general.
Periods and Frequency of a Wave
The number of times a wave cycles per second is called the frequency of a wave. The measurement of frequency is done through cycles per second or through Hertz (Hz). Generally, the ‘ f ’ letter is used to denote frequency.
The time taken in order to complete one vibration is known as the time period. A period is measured through time units, generally in seconds. It is represented through the uppercase letter ‘T’.
Time period and Frequency are somewhat related to each other. Frequency and time period are considered to be inversely proportional to each other and are reciprocals to each other.
\[ \text { period }= 1 \text { frequency } \text { or } T=1 f \]
\[\text { frequency } = 1 \text { period } \text { or } f=1 T \]
Speed or Velocity of a Wave
The speed of propagation of any wave is considered an important factor, it determines how fast a wave is moving through the disturbances. The speed of the wave is somewhat dependent on the medium it travels through. The speed of the wave varies in different mediums, it changes depending upon the medium it travels through.
Velocity = Frequency x Wavelength
or
V = F x λ
The velocity or speed of the wave is calculated by multiplying the frequency by wavelength. It is represented through the letter ‘v’.
For Example: Let the frequency of the wave be $5hz$ and the wavelength is $4m$. Then calculate the velocity of the wave.
Ans. Since, Velocity = Frequency x Wavelength
Then, velocity of wave = 5 x 4 = 20 $\mathrm{~m} \mathrm{s}$
Summary
The waves are considered an important element of the physical sciences and several of our daily life habits are successful only due to the presence of waves in our environment. Several parts of waves like the amplitude of a wave have their own significance and help us calculate different parts of the wave.
FAQs on The Amplitude of a Wave
1. What is the amplitude of a wave in simple terms?
The amplitude of a wave is its maximum displacement or distance from its equilibrium (or rest) position. In simpler terms, it's the 'height' or 'intensity' of the wave. For instance, in a water wave, the amplitude is how high a crest rises above the calm water level.
2. How do you measure the amplitude of a wave on a diagram?
To measure amplitude, you find the distance from the central line (equilibrium position) to the top of a crest or the bottom of a trough. It is important to remember that amplitude is not the total distance from a crest to a trough; that measurement is equal to twice the amplitude.
3. What is the real-world significance of a wave's amplitude?
A wave's amplitude directly relates to the amount of energy it carries. More energy results in a larger amplitude. Here are some examples:
- Sound Waves: A larger amplitude makes a sound louder.
- Light Waves: A larger amplitude makes light appear brighter.
- Water Waves: A wave with a large amplitude is taller and more powerful.
4. What happens to the amplitude of a wave as it travels away from its source?
Generally, the amplitude of a wave decreases as it gets farther from its source. This happens because the wave's energy spreads out over a larger area, and some energy can be lost to the medium it travels through. For example, a sound becomes fainter as you move away from the speaker. This effect is known as attenuation or damping.
5. How is amplitude different from frequency in a wave?
Amplitude and frequency describe two separate characteristics of a wave.
- Amplitude relates to the wave's energy or intensity (e.g., loudness or brightness).
- Frequency relates to the number of waves that pass a point per second (e.g., the pitch of a sound).
6. Can a wave exist with zero amplitude?
Yes. A state of zero amplitude means there is no displacement from the equilibrium position. This is simply the 'at rest' or undisturbed state of the medium. For example, the surface of a perfectly still pond represents a water wave with zero amplitude.
