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Lauren Reynolds
Chapter 17 and 18 Vocab
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 of the wave below the rest position. |
Transverse Waves | 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 | 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 time intervals. |
Period | The time required for one cycle, a complete motion that returns to its starting point. |
Frequency | The number of complete cycles in a given time. |
Hertz | Cycles per second, or what frequency is measured in. |
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 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 a smaller displacements. |
Standing Wave | A wave that appears to stay in one place- it does not seem to move through the medium. |
Node | A point on a 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 | Exerts electric forces on charged particles in a region of space. |
Magnetic Field | Produces magnetic forces in a region of space. |
Electromagnetic Radiation | The transfer of energy by electromagnetic waves traveling through matter or across space. |
Photoelectric Effect | The emission of electrons from ametal 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 temperature. |