WAVES

CREATE A FLIP BOOK Mechanical Wave Transverse Compressional Diagram/Facts Examples Properties

Wave Definition: A disturbance that transfers energy from place to place. What carries waves? A medium, a medium is the material through which a wave travels. A medium can be a gas, liquid, or solid.

Not all waves require a medium in which to travel. Light from the sun travels through empty space.

What causes waves? Waves are created when a source of energy causes a medium to vibrate. A vibration is a repeated back and forth or up and down motion.

Waves are classified into 2 TYPES according to HOW THEY MOVE

Transverse Wave Transverse means across. The highest parts are called crests the lowest parts are called troughs. Waves that move the medium at right angles to the direction in which the waves are traveling.

Draw Transverse wave and label: crest & trough

EXAMPLES Light waves Electromagnetic waves X-rays Gamma Rays Microwaves Ultraviolet waves Radio waves

Compressional Wave Matter vibrates in the same direction as the wave travels. The parts, where the coils are close together are called compressions, the parts where the coils are spread out are called rarefactions.

[Compressional]

Draw a Compressional wave: label compression & rarefaction

EXAMPLE Sound waves

BELL JAR VIDEO

HOMEWORK Compare and contrast transverse and compression waves. You can make a double bubble or just use your flip book…write a paragraph that compares and contrasts transverse and compression waves.

Types of Waves Review Transverse Wave crests and trough are perpendicular to the direction of Motion. Compression [longitudinal] wave Compressions and rarefactions are in the direction of motion (parallel to the motion).

Basic Properties of Waves Amplitude Wavelength Frequency Speed

Amplitude Amplitude is the maximum distance the particles of the medium carrying the wave move away from their rest positions. rest

The greater the amplitude the greater the amount of energy. The farther the medium moves as it vibrates the larger the amplitude of the resulting waves. The greater the amplitude the greater the amount of energy. Smaller amplitude Smaller amount of energy: dim lights, low sounds greater amplitude Greater amount of energy: brighter lights, louder sounds

Wavelength A wave travels a certain distance before it starts to repeat. The distance between two corresponding parts of a wave is its wavelength.

In a transverse wave measure from crest to crest or trough to trough.

In a longitudinal/compressional wave, measure from one compression to the next.

Frequency The number of complete waves that pass a given point in a certain amount of time. AKA number of vibrations per second. Frequency is measured in hertz (Hz).

Frequency Frequency = number of WAVES passing a stationary point per second (Hertz)

Higher frequencies result in shorter wavelengths. Longer wavelengths result in smaller frequencies.

Both wavelength and frequency determine the color of light and the pitch [highness or lowness] of sound.

Speed The speed of a wave is a property of the medium - changing the speed actually requires a change in the medium itself. If the medium does not change as a wave travels, the wave speed is constant.