1. Properties of Waves 8.1

2. Mechanical Waves Require a medium to transfer energy from one place to another.

3. Transverse and Longitudinal Waves Wave pulse—single disturbance that travels through the medium Periodic wave—if the source vibrates repeatedly Transverse wave—the particles in the medium move in a direction perpendicular to the direction of wave motion Longitudinal wave—the particles in the medium move in the same direction (or parallel to) the wave

4. Amplitude The distance from the equilibrium position to the crest of a wave amplitude

5. Wavelength λ—the shortest distance between two points of a wave where the pattern repeats λ λ

6. Frequency and Period Frequency (f)—the number of waves (cycles) per unit time that pass a point in the medium— Hz (hertz) Period (T)—the amount of time it takes for one complete wavelength to pass a point in the medium

7. Speed Velocity = distance traveled (wavelength) divided by time interval Velocity = wavelength X frequency

8. Sound Longitudinal mechanical wave that causes pressure variations in a medium Compression—a region of increased air density and pressure Rarefaction—a region of decreased air density and pressure When you hear sound, energy is transferred from a source to your ears, which causes your eardrum to vibrate.