| Waves and Speed |
| In opposite to the longitudinal sound waves in air, water waves are transversal waves, where the particle oscillation is perpendicular to the direction of wave propagation. The sound waves can be characterized by the frequency, wave length, wave propagation velocity and the amplitude from the oscillations. The frequency f is the number of harmonic oscillations of a particle per second and is expressed in Hz (1Hz=1/s) or kHz (kilo hertz; 1 kHz=1000 Hz). The wave length λ is the distance between particles oscillating in phase, e.g. between two maxima, and is expressed in m. The propagation velocity of the wave front is called the speed of sound c and is expressed in m/s. The speed of sound must not be mistaken for the particle velocity u. The speed of sound in air is independent of the frequency and can be calculated as a function of the temperature. c=331.4 + 0.607*t (t – temperature in degree Celsius) For a normal temperature range around 20°C you can calculate with a constant speed of air of about: c ≈ 340 m/s Between the wave length λ, the frequency f and the speed of sound c is the following relation:  |
