2. Wave – any disturbance that transmits energy through matter or space Medium – a substance through which a wave can travel. Can be a solid, liquid, or gas Mechanical Waves – do require a medium (example: sound) Electromagnetic waves – do not require a medium (example: light)

3. Transverse waves – particles vibrate with up- and-down motion Crest – highest point of a transverse wave Trough – lowest point of a transverse wave

4. Longitudinal wave – particles of the medium vibrate back and forth along the path that the wave travels. Compression – when particles are crowded together Rarefaction – when particles are less crowded than normal

5. Surface Wave – when waves occur at or near the boundary between two media

6. Amplitude – the maximum distance the wave vibrates from its rest position Wavelength – the distance between any two adjacent crests or compressions in a series of waves.

7. Frequency – the number of waves produced in a given amount of time. Measuring Frequency – count either the number of crests or the number of troughs that pass a point in a certain amount of time.

8. Higher frequency means more energy! It takes more energy to vibrate a rope quickly than to vibrate a rope slowly. Wave speed – the speed at which a wave travels The speed of a wave depends on the medium in which the wave is traveling. For example, the wave speed of sound in air is about 340 m/s but the wave speed of sound in steel is about 5200 m/s.

9. Information about qualities; information that can't actually be measured. Some examples of qualitative data are the softness of your skin, the grace with which you run, and the color of your eyes.

10. Information about quantities; that is, information that can be measured and written down with numbers. Some examples of quantitative data are your height, your shoe size, and the length of your fingernails.