Educator

Sound

• Sound waves are longitudinal.
• In a sound wave in air there is a succession of compressions (or condensations) and rarefactions.
• For humans, audible sound has frequencies between 20 Hz and 20 kHz.
• In air, at 0 °C, the speed of sound is 331 m/s. At other temperatures, it is (331 m/s)*SQRT (T/273), where T is the absolute temperature in Kelvin.
• Sound waves carry energy. The amount of energy transported is the power P. The sound intensity is the power that passes perpendicularly through a surface divided by the area of the surface.