Module 3 Part 3: Sound Waves Flashcards
what type of wave is sound
its is a mechanical and longitudinal wave
what frequencies are humans able to hear
20-20000 Hz
what are the types of sound (3)
Infra-sound
Audible sound
Ultra-sound
what is the range of infra-sound
less than 20 Hz
what is the range of audible sound
between 20-20 000 Hz
what is the range of ultra-sound
More than 20 000 Hz
what changes the speed of a wave
the medium it moves through
what is the approx speed of sound through air
340 m/s
what is the approx speed of sound through water
1500 m/s
what is the approx speed of sound through metal
3000 m/s
how is pitch determined
by the frequency of the sound wave
how is volume determined
by the amplitude of the sound wave
what is the symbol for sound intensity
I
relationship of sound intensity vs distance
I α 1/d²
what are beats
when two sounds of similar amplitude but slightly different frequency interact and create a regular pulse like sound
formula for frequency of beats
fᵦₑₐₜ = |f₁-f₂|
what is the Doppler effect
the apparent change in the frequency of a wave due to the relative motion of the source and observer
what is the equation for the Doppler effect
f’ = f (Vᵥᵥₐᵥₑ + Vₒᵦₛₑᵣᵥₑᵣ)/ (Vᵥᵥₐᵥₑ - Vₛₒᵤᵣ𝒸ₑ)
what is f’ in the Doppler effect equation
the observed frequency
what is f in the Doppler effect equation
the original frequency
what is Vᵥᵥₐᵥₑ in the Doppler effect equation
the speed of the waves
what is Vₒᵦₛₑᵣᵥₑᵣ in the Doppler effect equation
the speed of the observer
what is Vₛₒᵤᵣ𝒸ₑ in the Doppler effect equation
the speed of the source
what is V measured in
m/s
