Khan Academy Static

In these videos and articles you'll see visualizations of the propagation of sound waves, along with a visual definition of a sound wave's amplitude, period, frequency, and wavelength. You'll also learn how the speed of sound depends on the different characteristics of the medium. It will be shown how Mach numbers characterize faster than sound travel and their relationship to sonic booms. Also, you'll learn about the decibel scale, why sounds get softer, and how ultrasound medical imaging works.

10050_Production_of_sound.html

10052_Speed_of_Sound.html

10055_Decibel_Scale.html

10053_Relative_speed_of_sound_in_solids_liquids_and_gases.html

10051_Sound_Properties_Amplitude_Period_Frequency_Wavelength_.html

10057_Ultrasound_medical_imaging.html

10056_Why_do_sounds_get_softer_.html

10054_Mach_numbers.html