Acoustics


 * Wave types **

** Speed Distance travelled in unit time (m/S) Diferent waves travel at different speeds ** ** Frequency ** Numbers of complete waves in one second. In the numbers of waves that pass a point per second. This is measure in hertz (Hz) ** Wavelength ** Distance between matching points on the wave. This is sometimes called lambda £ and it is measure in meters (m). ** Longitudinal ** is a vibration parallel to direction of travel. Long waves vibrate parallel to the direction of travel of the wave. Sound waves are longitudinal.
 * Waves carry energy from one place to another sound, light and signal all travel in the form of moves. **

** Transverse ** Is a wave’s vibration at right angle to direction of travel of the wave. 

**Video** - Sound is normally caused by objects vibrating. - Object is a large make pick waves. - Larger objets make waves which create lower frecuency or lower pitch. - Smaller objetcs create more wavelenghts and, therefore, higher pitch. - Sound energy as it moves, is covering more area and therefore it´s geting quieter.

When two hands claps they vibrate but that it is not the source of noise, what we hear its acceleration moves. we fill this balloom with a fine powder to show the shock wave, the inside the ballom is high preasure, and when it burst, this preasure form a wave, which form the familiar bang that you hear, behind, this left a halo and this is evidences of the preasure wave or the shockwave.
 * Impulsive sources:**

So what couses a whip to crack? well its a mimi sonic boom. Now sonic boom its more often asociated with supersonic aircraft and with a space shuttle, imagine a bird going down the river you can see wave quakes coming out of the back, and the same thing its happends with aircraft. Now before the aircraft stay slower with the speed of the sound, then this wave can get out of the way, but as soon af the aircraft goes above the spedd of sound, this wave bunch togather and eventually form a shockwave, wich is the sonic boom you hear, and that speed is call mach one, wich is the spedd of sound. 
 * whips and sonic boom:**