Waves and sound

Waves and sound

1. waves transfer energy without transfering matter

2. Amplitude is the maximum displacement from the mean position in m

3. Wavelength is the shortest distance between any point on the wave and the equivilant point on the next in m

4. Frequency is the number of complete oscillations that take place in one second in Hz

5. Wave Speed = frequency X wavelength

6. Transverse wave is vibrating perpendicular to the direction of propagation of wave travel made of crests and troughs representing maximum and minimum displacement

7. Longitudinal wave is vibrating parallel to the direction of propagation of wave travel made of compression where particles are close together in a high pressure region and rarefaction where particles are far apart in a low presssure region

8. the Ripple Tank is used to study the properties of waves as the are produced from a high voltage motor and sent across obstacles so observe their effects

   • Reflection
     • the waves reflected from the surface at the same angle they strike it with no change in speed, wavelength nor frequency
     • responsible for Echoes of sound double the distance and time
   • Refraction
     • due to the change of wave speed and wavelength with constant frequency when changing medium densities
       • In shallow water, the ray bend toward the normal and it slow down with less wavelength. In deep water, the ray bend away from normal and speed up with more wavelength
   • Diffraction
     • the spreading of the wave around a corner which is only significant if the size of the gap is about the same as the wavelength so wider gaps produces less diffraction
       • Narrow opening give more curved wavefronts than wide opening which are only bent in the edges
       • there is no change in speed wavelength nor frequency only the shape of wavefronts
   • the volume of sound is determined by the amplitude while the pitch of sound is determined by the frequency
   • the transverse dampens after travelling some distance