2.  A mechanical wave is a rhythmic disturbance that carries energy through matter and space.  All mechanical waves are made by something that vibrates.

3.  Mechanical waves need a matter medium to travel through. ◦ Example of a medium is air, water, seismic  There are two basic types of mechanical waves: ◦ A. Transverse wave ◦ B. Compressional (longitudinal)

4.  A wave in which motion of the medium is a right angles to the direction of the wave.  Seismic waves and light http://www.youtube.com/watch?v=LyxLxx3xifo

5.  These are waves in which the movement of the medium is parallel to the direction of the movement of the waves.  Sound moves in a compressional wave ◦ http://www.youtube.com/watch?v=aguCWnbRETU http://www.youtube.com/watch?v=aguCWnbRETU

6.  The electromagnetic spectrum covers a wide range of wavelengths and photon energies.

7.  Wavelength-distance from a point on a wave to the same corresponding point on the next wave.  Frequency-number of waves that pass a point in one second. It is expressed in Hertz(Hz).  Crest- the point on a wave with a maximum upward displacement of the cycle.  Trough- the point on a wave with a minimum downward displacement of the cycle.

8.  Amplitude-the maximum amount of displacement of a particle on the medium from its rest position(equilibrium). Ex. From rest to crest.

9.  Wavelength has an inverse relationship to wave frequency.  Wave velocity depends on the type of wave and medium. ◦ Sound waves travel faster in a more dense medium, such as water.  Why? More atoms to carry the vibrations. ◦ Light waves’ travel time is slower in more dense medium (ex. water), but faster in a vacuum.  Why? Light is interacting with the atoms.

10.  Waves transport energy along a medium without transporting matter.  The amount of energy carried by a wave is related to the amplitude of the wave.  The higher the wave is from the resting line the more energy is put in and vice-versa.