| A | B |
|---|
| motion | change in position relative to a frame of refference |
| wave | a rhythmic disturbance that travels thru matter or space |
| wave motion | means of transferring energy |
| 2 basic types of waves | longitudal and transverse |
| transverse wave | matter vibrates at right angles to the direction in which the wave travels |
| longitudal wave | matter vibrates back and forth along the path that the wave travels |
| periodic motion | motion that repeats itself over and over again |
| periodic wave | a motion that repeats at regular intervals & transfers energy but not mass |
| period | time it takes for a motion to repeat itself measured in seconds |
| frequency | how often a cycle repeats itself in a time unit |
| hertz | measurement of frequency |
| amplitude | max. distance a wave rises or falls as it travels |
| crest | maximum upward displacement |
| trough | maximum downward displacement |
| wavelength of a transverse wave | distance between two succesive crests |
| wave speed | frequency of the wave times the wavelength |
| diffraction | bending of waves around an obstacle |
| interference | how waves interact when they go thru the same portion od a medium at the same time |
| resonance | when the vibration of 1 system results in vibration of the other system at the same time |
| photons | tiny packets of energy |
| light waves | electromagnetic waves |
| electromagnetic spectrum | complete spectrum of light arranged in order of wavelengths |
| visible light | visible to the human eye |
| electromagnetic spectrum includes; | radio waves, infared waves, visible light, xrays, gamma rays |
| photons of visible light | are a moderate amount of energy |
| xrays are made up of; | high energy photons,which contain low energy photons |
| amplitude | loudeness of a sound wave |
| doppler effect | occurs when there is relative motion between the source of waves and the observer |
| reflection | when light bounces off a surface that does not absorb its energy |
| refraction | bending of light rays as they pass from 1 medium to another |
| dispersion | phenomenon of a prism separating light into it's components of color |
| lens | transparent material that refracts light |
| convex lens | thicker in the center than on the edges |
| concave lens | thicker on the edge than the center |
| focal point | the point at which light rays meet |
