1. WAVE MECHANICS BASIC MECHANICAL WAVES

2. Cyclical Motion  Cyclical motion is any type of motion that repeats itself over and over.  A pendulum is an example of cyclical motion. The pendulum swings back and forth.  Waves that we will be studying in this class are cyclical in nature. They are fluctuations that repeat themselves as they move through their medium.

3. Types of Waves  There are 2 main types of waves.  Transverse:  Longitudinal:

4. Features of Transverse Waves  A=Crest  B=Trough  C= Wavelength  E= Amplitude  D= Rest Position

5. Features of Longitudinal Waves  A=Area of Compression  B= Rarefaction

6. Transverse Waves Cont.  Transverse waves move through a medium perpendicular to the direction the particles vibrate.  Think of the T in transverse making a right angle with itself. This will help you remember that Transverse waves vibrate at 90 degree angles to their direction of motion.

7. Longitudinal Waves  Longitudinal waves are also known as compressional waves.  Longitudinal waves vibrate parallel to the direction they are moving. (The vibration seems to be in the same direction as the wave is moving.)  Sound waves are the most common example of longitudinal waves.

8. General Wave Facts  Mechanical waves are any type of wave that require a medium to move through.  The medium of a wave is the material that the wave travels through.  Sound waves are mechanical waves that require a medium of air in order to move.  The medium does not change its location as a wave travels through it. The medium only vibrates.  The energy of the wave is the only thing that moves.

9. Important Wave Velocities  Speed of Light = 300,000,000 m/s  (Can also be written as 3*10 8 m/s)  Speed of sound = 340 m/s  Varies with temperature. Cooler air means faster sound, warmer air means slower sound.

10. Wave Equations

11. VariableQuantityUnit vwvw Wave velocityMeter per second (m/s) (lambda) WavelengthMeter (m) (tau) PeriodSecond (s) FFrequencyHertz (Hz) or ‘per second’ (1/s or s - 1 )