Waves

Waves

Warmup: describe resonance

Wave

• a disturbance that propagates(transmitted) from place to place carrying energy

• Transverse waves- particles oscillate perpendicular to direction of propagation

• Longitudinal waves- particles oscillate parallel to direction of propagation

• Water waves- have properties of both wave types. particles move in a circular pattern

Wave properties

• Crests- the highest point of the wave

• Troughs- the lowest point on the wave- equal in magnitude to the crest

• Wavelength- distance over which a wave repeats-λ

• Speed of a wave= wavelength/period or wavelength x frequency

• applies to all waves no matter what

Sound waves travel in air with a speed of 343 m/s. The frequency of the lowest sound you can hear is 20 Hz, and the frequency of the highest sound you can hear is 20 kHz. Find the wavelengths of sound waves having frequencies of 20 Hz and 20 kHz.

Wave types and movement

• Mechanical waves- waves that move through a medium- sound and water waves

• Electromagnetic- waves that move through a vacuum- light, UV, Gamma, etc

• Waves can reflect in two different ways

• A wave will invert when reflected off a fixed point

• A wave will remain uninverted when reflected off an unfixed point

Wave interaction

• The principle of superposition states that a resultant wave is the sum of the individual waves.

• Waves combine in the same space by simply adding together

• You can have constructive interference that makes a larger wave than initially.

• You can have destructuve interference that makes a small wave