click below
click below
Normal Size Small Size show me how
Hristina Bundalo
Chapter 17+18
Term | Definition |
---|---|
mechanical wave | disturbance in matter that carries energy from one place to another |
medium | material in which a wave travels through |
crest | highest point of the wave above the rest position |
trough | lowest point of the wave below rest position |
transverse wave | wave that causes the medium to vibrate at right angles to the direction in which the wave travels |
compression | area where particles in the medium are spaced close together |
rarefaction | area where particles in the medium are spread far apart |
longitudinal wave | wave in which the vibration of the medium is parallel to the direction the wave travels |
surface wave | wave that travels along the surface separating two media |
periodic motion | any motion that repeats at regular times intervals |
period | the time required for one cycle, a complete motion that returns to its starting point |
frequency | number of complete cycles in a given time |
hertz | cycles per second |
wavelength | distance between a point on one wave and the same point on the next cycle of the wave |
amplitude | of a wave is the maximum displacement of the medium from its rest position |
reflection | occurs when a wave bounces off a surface that it cannot pass through |
refraction | the bending of a wave as it enters a new medium at an angle |
diffraction | the bending of a wave as it moves around an obstacle or passes through a narrow opening |
interference | occurs when two or more waves overlap and combine together |
constructive interference | occurs when two or more waves combine to produce a wave with a larger displacement |
destructive interference | occurs when two or more waves combine to produce a wave with smaller displacements |
standing wave | wave that appears to stay in one place, it doesn't seem to move through the medium |
node | a point on the standing wave that has no displacement from the rest position |
antinode | a point where a crest or trough occurs midway between two nodes |
electromagnetic waves | transverse waves consisting of changing electric fields and changing magnetic fields |
electric field | in a region of space exerts electric forces on charged particles |
magnetic field | a region in space produces magnetic forces |
electromagnetic radiation | the transfer of energy by electromagnetic waves traveling through matter or across space |
photoelectric effect | the emission of electrons from a metal caused by light striking the metal |
photons | packets of electromagnetic energy |
intensity | the rate at which a waves energy flows through a given unit of area |
electromagnetic spectrum | the full range of frequencies of electromagnetic radiation |
amplitude modulation | the amplitude of the wave is varied, the frequency remains the same |
frequency modulation | the frequency of the wave is varied, the amplitude remains the same |
thermograms | color-coded pictures that show variations in temperature |