click below
click below
Normal Size Small Size show me how
Randalynn Sharp
Chapter 17 Vocabluary
| 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 a wave above the rest posistion. |
| Transverse wave | 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 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 cycle, a complete motion that returns to its starting point. |
| Frequency | The number of complete cycles in a given time. |
| Hertz | Cycles per second. |
| 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 abstacle or passes through a marrow opening. |
| Interference | Occurs when two or more wave 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 displacement. |
| Standing wave | A wave that appears to stay in one place- it does not move through the medium. |
| 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 | In a region of space, it exerts electric forces on charged particles. |
| Magnetic field | In a region of space, it 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 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. |
| Frequency modulation | The frequency of the wave is varied. |
| Thermograms | Are color-coded pictures that show variations in temperature. |