Key Properties: Frequency, amplitude, wavelength, and speed
Nature of Sound Waves
Sound is created by a vibrating object.
Disturbances caused by vibration move through a medium.
Sound is a mechanical wave, propagating by particle-to-particle interaction.
Sound travels through fluids as a longitudinal wave (no crest or trough).
Observed as alternating compressions and rarefactions.
Soundwave transports energy without moving physical matter.
Key Properties of Sound Waves
Frequency
Refers to how often a periodic event repeats per second.
Measured in Hertz (Hz).
Vibrational frequencies of particles are synchronized with the source.
Perceived as the pitch of the sound:
High pitch = high frequency
Low pitch = low frequency
Audible range: 20 Hz to 20,000 Hz
Below 20 Hz: Infrasonic
Above 20,000 Hz: Ultrasonic
Amplitude
Maximum displacement of a particle from its rest position.
Higher amplitude = louder and more intense sound.
Amplitude reflects amount of energy in the wave.
Wavelength
Length of the repeating unit within a wave pattern.
For longitudinal waves:
Distance from compression to compression or rarefaction to rarefaction.
Inversely related to frequency:
High frequency = short wavelength
Low frequency = long wavelength
Speed
Distance traveled by compression per unit time.
Dependent on properties of the medium:
State of matter: Solids > Liquids > Gases
Example speeds:
Solid aluminum: 5100 m/s
Water: 1400-1500 m/s
Air: 340-350 m/s
Temperature affects speed in air:
Speed = 331.65 + (0.6 * Temperature in °C)
Speed is independent of frequency, wavelength, or amplitude.*
Wave Equation
Mathematical relationship: Speed (V) = Frequency (F) * Wavelength (λ)
Speed is constant in a uniform medium.
Frequency and wavelength inversely related:
Doubling frequency halves wavelength and vice versa.*
Conclusion
Encourage engaging with additional resources such as MindsOn Physics mission, Concept Builder, and tutorial page on the website for deeper understanding.
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