Introduction to Waves and Wave Types

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Questions and Answers

What is the maximum displacement of the disturbance from the equilibrium position called?

Amplitude

What is the term for the highest point in a wave?

Crest

What is the term for the lowest point in a wave?

Trough

What is the term for the length of the wave between two crests or two troughs?

Wavelength Signup and view all the answers

In which type of wave does the medium oscillate parallel to the direction of the wave pulse?

Longitudinal Waves Signup and view all the answers

What is Compression?

Areas where the wave is closest together Signup and view all the answers

In which type of wave does the medium oscillate perpendicular to the direction of the wave pulse?

Transverse Waves Signup and view all the answers

What's Rarefaction?

Areas where the wave is most spread out. Signup and view all the answers

Example of longitudinal wave.

Sound Signup and view all the answers

Example of Transverse wave?

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What's a Period? Symbol? Unit? Formula?

Period is the time in which a wave completes a full cycle (oscillation) Signup and view all the answers

What's Sound?

Sound is a pressure wave caused by vibration in a medium. A vibrating particle will collide with other particles making them vibrate too. Signup and view all the answers

What's Frequency? Symbol? Unit? Formula?

Frequency is the number of cycles completed in a second. Symbol: f, Unit: Hz (Hertz), Formula: f= #cycles/∆T. Signup and view all the answers

What's Longitudinal wave pattern?

When vibrating particles transfer their energy to many particles. Signup and view all the answers

How do High & Low pressure are caused?

By particles be squished together or far apart. Signup and view all the answers

Sound waves speed in liquid, gas & s solid (from slowest to fastest)

Gas, Liquid, Solid Signup and view all the answers

Warner temperatures = sound travel fast

True Signup and view all the answers

What is an echo?

When sound collides with a solid surface, it reflects back. Due to how long sound traveling takes, there will be a delay. Signup and view all the answers

Humans hear sound between

20 to 20,000 Hz Signup and view all the answers

What's Pitch?

How we hear sound wave's frequency with our ears. Signup and view all the answers

Lower the pitch = Higher the frequency

False Signup and view all the answers

When does Doppler effect occur?

Occurs when the source of the wave is moving with respect to the observer. Signup and view all the answers

As source approaches, waves get ____ (λ )

Compressed, decreases Signup and view all the answers

As source passes by, waves are ______ (λ )

Spread out, increases Signup and view all the answers

What is the only thing that changes in Doppler effect?

Wavelength Signup and view all the answers

What's Mach Speed?

It describes how many times the speed of sound is travelling. Signup and view all the answers

What's Sonic Boom?

If an object travels at the the speed of sound, its sound waves will overlap. Air particles are highly pressurized (compressed), creating a sonic boom. This can damage trees, plants, and even shatter windows, because the frequency is very high! Signup and view all the answers

What's mach cone?

When going faster than the speed of sound, a cone shape sound wave pattern called a mach cone forms. Signup and view all the answers

How do noise cancellation work?

Noisecancellation headphones will remove background noise by recording the sound from its surroundings and replaying it out-of-phase (1/2 wavelength delay), causing complete destructive interference. Signup and view all the answers

Infrasound?

Frequency below human hearing Signup and view all the answers

Ultrasound?

Above human frequency hearing. Signup and view all the answers

Study Notes

Waves and Sound

The maximum displacement of the disturbance from the equilibrium position is called amplitude.
The highest point in a wave is called a crest.
The lowest point in a wave is called a trough.
The length of the wave between two crests or two troughs is called the wavelength.

Types of Waves

In a longitudinal wave, the medium oscillates parallel to the direction of the wave pulse.
In a transverse wave, the medium oscillates perpendicular to the direction of the wave pulse.
Compression is a region where the particles are close together.
Rarefaction is a region where the particles are spread apart.

Examples of Waves

An example of a longitudinal wave is a sound wave in a gas.
An example of a transverse wave is a light wave.

Properties of Waves

A period is the time taken by the wave to complete one oscillation.
The symbol for period is T and its unit is seconds (s).
The formula for period is T = 1/f, where f is the frequency.
Sound is a form of mechanical wave that requires a medium to propagate.

Frequency

Frequency is the number of oscillations or cycles per second.
The symbol for frequency is f and its unit is Hertz (Hz).
The formula for frequency is f = 1/T, where T is the period.

Longitudinal Wave Pattern

In a longitudinal wave, the particles oscillate back and forth along the direction of propagation.

Pressure and Temperature

High pressure is caused by the particles being compressed, and low pressure is caused by the particles being rarefied.
In warmer temperatures, sound travels faster.

Echoes and Human Hearing

An echo is a repeated sound that is reflected back to the listener.
Humans can hear sound between 20 Hz and 20,000 Hz.

Pitch and Frequency

Pitch is the perception of the frequency of a sound wave.
Lower the pitch means higher the frequency.

Doppler Effect

The Doppler effect occurs when there is relative motion between the source and the observer.
As the source approaches, waves get shorter (λ decreases).
As the source passes by, waves are stretched out (λ increases).
The only thing that changes in the Doppler effect is the wavelength.

Speed of Sound and Mach Speed

The speed of sound in liquid, gas, and solid (from slowest to fastest) is approximately 343 m/s, 1,482 m/s, and 5,960 m/s respectively.
Mach speed is the speed of an object as a multiple of the speed of sound (M = v / v_sound).

Sonic Boom and Mach Cone

A sonic boom is a shockwave produced when an object breaks the sound barrier.
A mach cone is the cone-shaped shockwave produced by an object traveling at supersonic speeds.

Noise Cancellation and Infrasound/Ultrasound

Noise cancellation works by producing a sound wave with the same amplitude but opposite phase to cancel out the noise.
Infrasound is sound with frequencies below 20 Hz, while ultrasound is sound with frequencies above 20,000 Hz.

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Description

This quiz provides an introduction to the concept of waves, including their characteristics and types. It covers the definition of waves, their behavior, and the distinction between transverse waves and other types.