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TLHS Phy Sci #8
All About Waves
| Term | Definition |
|---|---|
| wave | repeating disturbance that transfers energy through matter or space |
| medium | matter through which a wave travels |
| mechanical wave | waves that can only travel through matter |
| transverse wave | particles in the medium move at right angles (perpendicular) to the direction the wave travels |
| longitudinal wave | particles in the medium move the same direction (paralel) to the direction the wave travels |
| crest | high point of a transverse wave |
| trough | low point of a transverse wave |
| compression | dense region on a longitudinal wave |
| rarefaction | less dense region on a longitudinal wave |
| wavelength | distance between one point on a wave and the nearest point just like it |
| frequency | number of waves that pass a fixed point each second |
| period | amount of time it takes one wavelength to pass a point |
| amplitude | measure of the size of the disturbance of the wave |
| reflection | wave strikes and object and bounces off it |
| refraction | bending of a wave caused by a change in speed when moving from one medium to another |
| diffraction | bending of a wave around an object |
| interference | process of two or more waves overlapping and combining to form a new wave |
| constructive interference | two waves combine to form a new wave larger than the originals |
| destructive interference | two waves combine to form a new wave smaller than the originals |
| standing wave | waves of equal length and amplitude travel in opposite directions and interfere with each other |
| nodes | locations where interfering waves always cancel |
| resonance | object is made to vibrate by absorbing energy at its natural frequencies |
| sound | longitudinal waves that need to travel through a medium |
| intensity | amount of energy that passes through a certain area in a specific amount of time |
| loudness | perception of sound volume depends on sound intensity |
| decibel | unit of sound |
| dB | decibel |
| pitch | how high or low a sound seems to be, primarily related to the frequency of the wave |
| Doppler effect | change in wave frequency due to a wave source moving past an observer |
| electromagnetic waves | wave made of vibrating electric charges that do not need a medium |
| photon | mass-less bundle of energy that behaves like a particle |
| electromagnetic spectrum | arrangement of electromagnetic waves based on the frequency of the wave |
| radio waves | long electromagnetic wave with low frequency, longest wave |
| microwaves | electromagnetic waves with wavelengths between 0.1 mm and 30 cm, 2nd longest wave |
| infrared waves | electromagnetic wave that transfers thermal energy, 3rd longest wave |
| visible light | range of electromagnetic waves that can be detected by the human eye, mid-length wave |
| ultraviolet wave | electromagnetic wave that can enter cells, 3rd shortest wave |
| x - rays | electromagnetic wave that can enter soft tissue, but not dense tissue like bone, 2nd shortest wave |
| gamma rays | electromagnetic waves with the shortest wavelengths and highest frequencies |
| opaque | material only absorbs and reflects light, no light passes through, not see through |
| translucent | transmit light but also scatter it, objects on the other side looks blurry |
| transparent | transmit light without scattering it, can see clearly the object on the other side |
| reflection | wave bounces off the surface of material |
| refraction | speed of wave changes as it passes through different mediums, and the wave bends |
| mirage | refraction of light through air layers of different densities |
| color | depends on the wavelength reflected by an object |
| filter | transparent material that selectively transmits light |
| pigment | colored material used to change the color of a substance |