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Lisa Gabel
Chapter 17
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 a transverse wave. |
Trough | The lowest point of a transverse wave. |
Transverse wave | A wave that causes a medium to vibrate at right angle to the direction. In which the wave travels. |
Compression | An area of a longitudinal wave where the particles of the medium are close together. |
Rarefaction | An area of longitudinal wave where the particles of the 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 separating two media. |
Periodic motion | Any motion that repeats at regular time intervals. |
Period | The time required for one complete cycle of a periodic motion. |
Frequency | The number of complete cycles per unit time for a periodic motion. |
Hertz | The unit of measure for frequency, equal to one cycle per second. |
Wavelength | The distance between a point on a wave and the same point on the next cycle of the wave. |
Amplitude | The maximum displacement of a medium from the rest position. |
Reflection | The interaction that 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 | The interaction of two or more waves that combine in a region of overlap. |
Constructive interference | The interaction among two or more waves in displacement combine to produce a wave with larger displacement. |
Destructive interference | The interaction among two or more waves in which displacements combine to produce waves with a smaller displacement. |
Standing wave | A wave that appears to stay in one place and does not seem to move through a medium. |
Node | A point on a standing wave that has no displacement from the rest position. |
Antinode | A point of maximum displacement midway between two nodes in a standing wave. |
Electromagnetic Waves | A transverse wave consisting of changing electric and changing magnetic fields. |
Electric field | A field in a region of space that exerts electric forces on charged particles; a field produced by electric charges or by changing magnetic fields. |
Magnetic field | A field in a region of space that exerts magnetic forces' a field produced by magnets, by changing electric fields, or by moving charges. |
Electromagnetic radiation | The transfer of energy by electromagnetic waves. |
Photoelectric effect | The emission of electrons from a metal caused by light striking the metal. |
Photons | A packet 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 electromagnetic radiation. |
Amplitude modulation | A method of transmitting a radio signal in which the amplitude of the carrier waves varies while its frequency remains the same. |
Frequency modulation | A method of transmitting a radio signal in which the frequency of the carrier wave varies while its amplitude remains the same. |
Thermograms | A color- coated picture using variations in infrared radiation to show variations in temperature. |