2. What are Waves? A wave is a disturbance that transfers energy from place to place. Energy – the ability to do work The material through which a wave travels is called a medium Ex: Gases (air), liquids, solids Waves that require a medium are called mechanical waves

3. What causes waves? Mechanical waves are produced when a source of energy causes a medium to vibrate. Vibration- a repeated back-and-forth or up-and-down motion

4. Types of waves Waves are classified by how they move. Transverse waves- waves that move the medium at right angles to the direction in which the waves travel

5. Transverse Waves The high part of a transverse wave is called a crest The low part of a transverse wave is called a trough

6. Longitudinal Wave Longitudinal waves move the medium parallel to the direction in which the waves travel.

7. Longitudinal Waves Compression- area of longitudinal wave where the coils are close together Rarefaction- area of longitudinal wave where the coils are spread out, or rarefied

8. Properties of Waves Amplitude – the maximum distance the particles of the medium carrying a wave move away from their rest position. Wavelength – the distance between two corresponding parts of a wave. (crest-to-crest, trough- to-trough) Frequency – the number of complete waves that pass a given point in a certain amount of time. Speed – how far the wave travels in one unit of time.

10. Formulas Speed = wavelength x frequency (S = W x F) Frequency = Speed / Wavelength (F = S / W) Wavelength = Speed / Frequency (W = S /F)