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Ally Brown
Chapter 17/18
| Term | Definition |
|---|---|
| Mechanical Wave | A disturbance in matter that carries energy from one place to another. |
| Medium | The material through which a wave travels |
| Crest | The highest point of the wave above the rest position |
| Trough | The lowest point below the rest position |
| Transverse Wave | A wave that causes the medium to vibrate at right angles to the direction in which the wave travels |
| Compression | An area of where the particles in a medium are close together |
| Rarefaction | An area where the particles in a medium are spread out |
| Longitudinal Wave | A wave in which the vibration of the medium is parallel to the direction the wave travels |
| Surface Wave | A wave that travels along a surface seperating two media |
| Periodic Motion | Any motion that repeats at regular intervals |
| Period | The time required for one cycle |
| Frequency | The number of complete cycles in a given time |
| Hertz | Cycles per second, measures frequency. |
| Wavelength | The distance between a point on one wave and the same point on the next cycle of the wave. |
| Amplitude | The maximum displacement of a point 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 or combine |
| 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 | A wave that appears to stay in one place |
| Node | A point on a 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 | A region of space exerts electric forces on charged particles |
| Magnetic Field | A region of space produces magnetic forces |
| Electromagnetic Radiation | The transfer of energy bu 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 wave's 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 temperatures. |