The Doppler Effect - Sound Waves

Question	Answer
Any sound source produces sound waves	They leave the source like ripples on water
The speed at which these waves travel depend on what medium they travel through	Sound travels faster through denser materials
Sound travels at 340 \[m^s\] in air	And travels at 1497 \[m^s\] in water
The equation c=fλ is extremely useful	c = speed of sound λ = wavelength f = frequency
When the sound source in stationary, the waves have a uniform wavelength \[\lambda\] between them	Image: doppler1.gif (image/gif)
When the source is moving, the ripples grow closer together in the direction of motion of the source	This means that the wavelengths grow closer in the direction of motion of the source
Because the frequency and wavelength are inversely proportional...	When the wavelength is smaller, the frequency is higher!
When the source is moving away from you, the wavelength becomes larger...	So the frequency is higher!
So, when an sound source moves closer it sounds louder	And when it moves away, it sounds quieter!

Resource summary

	Created by leonie.examtime over 10 years ago

	Copied by ed.wilson89 over 10 years ago