waves Flashcards
Transverse waves
.a wave in which the medium vibrates at right angles to the direction of its propagation. (it goes up and down)
Compression waves / longitudinal wave
a longitudinal wave created in a fluid by a compressing force, e.g. a sound wave in air
Frequency
the rate per second of a vibration constituting a wave, either in a material (as in sound waves) (changes pitch)
Hertz (Hz)
what frequency is measured in
Pitch
the degree of highness or lowness of a tone: (distance between crests)
Wavelength
distance between crests
Radio waves
low energy waves used to communicate over long distances through Radio and TV
Electromagnetic spectrum
complete ranger of wavelengths of energy radiated as electric and magnetic fields
infra-red
invisible to human eye. is sensed as heat
visible light
light we can see (rainbow colours)
Ultra-Violet (UV)
invisible to human eye. to much causes sunburn
X-rays
have enough energy to pass through human flesh. can be used to kill cancer cells etc.
Gamma Rays
have more energy than X-rays. often produced as a cause of nuclear reactions
Reflection
light bouncing off a surface
luminous
objects that emit light
