Waves Flashcards
(15 cards)
frequency
the number of cycles a wave completes in a period of time; the number of times something happens in a period of time
Period
A period is the name given to a horizontal row of the periodic table. The periodic table has seven periods. Apart from period 1, every period begins with an alkali metal and ends with a noble gas. Period 1 contains only two elements: hydrogen and helium.
wavelength
the distance between one peak and the next on a wave
crest
the highest point of a wave
trough
Waves have moving crests (or peaks) and troughs. A crest is the highest point the medium rises to and a trough is the lowest point the medium sinks to. Crests and troughs on a transverse wave are shown in Figure 8.2. Figure 8.2: Crests and troughs in a transverse wave.
medium
A substance that makes possible the transfer of energy from one location to another, especially through waves. For example, matter of sufficient density can be a medium for sound waves, which transfer mechanical energy.
amplitude
height or “strength” of a wave
longitudinal wave
a wave vibrating in the direction of propagation.
electromagnetic spectrum
the range of wavelengths or frequencies over which electromagnetic radiation extends.
transverse wave
transverse wave. A wave that oscillates perpendicular to the axis along which the wave travels. Electromagnetic waves are transverse waves, since the electric and magnetic fields oscillate at a right angle to the direction of motion.
Compression
Compression. A compression is a region in a longitudinal wave where the particles are closest together.
rarefaction
Rarefaction. A rarefaction is a region in a longitudinal wave where the particles are furthest apart.
reflection
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves.
refraction
the fact or phenomenon of light, radio waves, etc. being deflected in passing obliquely through the interface between one medium and another or through a medium of varying density.
diffraction
Diffraction is defined as a process by which light waves break up into dark and light bands or into the colors of the spectrum. Light passing through a narrow opening in the blinds, causing bright and dark shadows and patterns to fall across the floor is an example of defraction.
