2. Types of Waves Transverse Wave v f = frequencyf = waves/second1wave/second = 1 Hertz λ = wavelengthλ = distance crest to crestλ is measured in meters v = speed of the wavev is measured in m/s Crest Trough v High Compression Low compression Longitudinal Wave λ = distance from high compression to high compression. Water waves are transverse waves. Sound waves are longitudinal waves.

3. Periodic Waves Periodic Wave v = f decreases v f = frequencyf = waves/second1wave/second = 1 Hertz λ = wavelengthλ = distance crest to crestλ is measured in meters v = speed of the wavev is measured in m/s If v is constant, = 1/f As f increases, As increases, f decreases. Crest Trough

4. Sound Waves v = f v What is the wavelength of middle C? λ = v/f Speed of sound in air ≈1,100 ft/s335 m/s750 mi/h f = 256 Hz λ = 1100/256 λ = 4.30 ft If f is doubled f = 512 Hz, what is the wavelength of the wave? v = f λ = v/fλ = 1100/512 λ = 2.15 ft When f is doubled, the wavelength is half as great?

5. Frequency and Wavelength λ is largerf is lower λ is smallerf is higher Low pitched sound. High pitched sound. Humans can hear between 20 and 20,000 HZ.

6. Interference Constructive Interference Destructive Interference Crest + Crest Crest + Trough