Sound Flashcards
(21 cards)
What is sound defined as?
A series of disturbances in matter that the human ear can detect
What are the three elements necessary for the transmission and reception of sound?
- Source
- Medium for carrying the sound
- Detector
How is sound produced when a bell is struck?
The bell vibrates, disturbing the surrounding air particles which transmit the vibrational disturbance in a wave
What type of waves are water waves considered?
Transverse waves
What are longitudinal waves?
Waves where particles of the medium vibrate back and forth in the direction of wave propagation
What happens when the tine of a tuning fork moves outward?
The air is compressed, raising its momentary pressure
What causes a rarefaction wave?
The inward movement of the tine of a tuning fork that reduces air pressure
What two physical properties govern the velocity of sound?
- Density
- Elasticity
In general, how does the speed of sound vary among different states of matter?
Fastest in solids, slower in liquids, slowest in gases
What is the speed of sound in air at 0 °C?
1,087 feet per second (fps)
What does the Mach number represent?
The ratio of the speed of an aircraft to the speed of sound
What is the relationship between pitch and frequency?
Pitch is proportional to the frequency of sound
How does loudness relate to the amplitude of vibrations?
Loudness depends on the amplitude of the vibrations of the sound waves
What is sound intensity measured in?
Decibels (dB)
True or False: One decibel (dB) is the smallest change in sound intensity that the human ear can detect.
True
What is the Doppler Effect?
The change in frequency of sound from a moving object as it approaches or moves away
What phenomenon occurs when an airplane travels at or above the speed of sound?
Sonic boom
What is resonance?
The transfer of wave energy between two pieces of matter with the same natural frequency
Fill in the blank: The greater the pressure variations in a sound wave, the more _______ the sound wave is.
intense
What is an example of harmonic motion?
- Motion of a clock pendulum
- Balance wheel in a watch
- Piston in a reciprocating engine
