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Danielle Easterday
Chapter 17 Vocab.
| Term | Definition |
|---|---|
| Mechanical Wave | Is 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 point. |
| Trough | The lowest point below the rest position. |
| Transverse Wave | Is a wave that causes the medium to vibrate at right angles to the direction in which the wave travels. |
| Compression | An area where the particles in a medium are spaced close together. |
| Rarefaction | An area where the particles in a medium are spread out. |
| Longitudinal Wave | Is a wave in which the vibration of the medium is parallel to the direction the wave travels. |
| Surface Wave | Is a wave that travels along a surface separating two media. |
| Periodic Motion | Any motion that repeats at regular time intervals. |
| Period | The time required for one cycle, a complete motion that returns to its starting point. |
| Frequency | Is the number of complete cycles in a given time. |
| Hertz | Frequency is measured in cycles per second. |
| Wavelength | Is the distance between a point on one wave and the same point on the next cycle of the wave. |
| Amplitude | 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 | Is the bending of a wave as it enters a new medium at an angle. |
| Diffraction | Is the bending of a wave as it moves around an obstacle or passes through a narrow opening. |
| Intereference | Occurs when two or more waves overlap and combine together. |
| Constructive Intereference | 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 a smaller displacements. |
| Standing Wave | Is a wave that appears to stay in one place-it does not seem to move through the medium. |
| Node | Is a point on a standing wave that has no displacement from the rest position. |
| Antinode | Is a point where a crest or trough occurs midway between two nodes. |
| Electromagnetic Waves | Are transverse waves consisting of changing electric fields and changing magnetic fields. |
| Electric Field | Is a region of space that exerts electric forces on charged particles. |
| Magnetic Field | Is a region of space that produces magnetic forces. |
| Electromagnetic Radiation | The transfer of energy by electromagnetic waves traveling through matter or across space. |
| Photoelectric Sffect | The emission of electrons from a metal caused by light striking the metal. |
| Photons | The packets of electromagnetic energy. |
| Intensity | Is 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 Moderation | The amplitude of the wave is varied. |
| Frequency Modulation | The frequency of the wave is varied. |
| Thermograms | Are color-coded pictures that show variations in temperature. |