WAVES: Class Wave A wave is a rhythmic disturbance that carries energy without carrying matter, through matter or empty space.

Waves that move through matter: Mechanical Mechanical Waves Waves that move through matter: Mechanical Mechanical waves move through matter: air, water, dirt, and other objects. Ex: Water! Energy is transferred from molecule to molecule they are transported without the molecules moving themselves The matter that it travels through is called a Medium Mechanical waves are produced by something vibrating Ex: Rope

Types of Mechanical Waves Transverse Wave energy causes matter in the medium to move up down or back and forth at right angles Rope Peaks: Crests Valleys: Trough Compressional Longitudinal Waves Matter moves forward and backward in the same direction Slinky

Electromagnetic Waves: Let’s use our book Electromagnetic waves move through empty space and matter;….. air, water, dirt, and other objects plus they can travel through space Ex. Sun rays, radio waves, infrared, X rays Magnetic Fields Transverse

Types of Wave There are two types of waves. Mechanical and Electromagnetic. Then there are two types of mechanical waves. WAVES Electromagnetic wave Mechanical Waves Compressional Wave Transverse Wave Transverse Wave Transverse wave

A transverse wave has different parts from a compressional wave.

Compressional wave The place where the coils are squeeze together is called a compression. The place where the coils are spread apart are called rarefactions. A series of compressions and rarefactions forms a compressional wave.

Properties of Waves: -Wavelength -Frequency -Amplitude -Speed

Wavelength The wavelength of a transverse wave is the distance between two adjacent crest or two adjacent troughs. The wavelength of a compressional wave is the distance between two adjacent compressions or rarefactions.

Frequency The frequency of a wave is the number of wavelengths that pass by a point each second. The SI unit for frequency is the hertz, (Hz). Frequency = Number of Wavelengths/Time

Frequency: how many wavelengths pass a point at a given time Note: as Frequency increases wavelength decreases

Solving Frequency What is the frequency of a wave if 10 wavelengths pass a point in 2 s? What is the frequency of a wave if 50 wavelengths pass a point in 5 s? What is the frequency of a wave if 100 wavelengths pass a point in 10s? What is the frequency of a wave if 482.5 wavelengths pass a point in 5s?(use a calculator)

Amplitude The amplitude of a wave is the maximum distance matter moves as the wave passes.

Amplitude and Energy The larger the amplitude of a wave, the more energy the wave carries.

Wave Speed The wavelength, frequency, and speed of a wave are related. To calculate the speed of a wave the following formula is needed: Wavelength(in m) = Wave speed (in m/s) Frequency (in Hz