| A | B |
|---|
| reflection | the bouncing back of an object or wave when it hits a surface through which it cannot pass |
| law of reflection | rule that the angle of reflection equals the angle of incidence |
| refraction | the bending of waves as they enter a new medium at an angle |
| diffraction | the bending of waves as they move around a barrier or pass through an opening |
| interference | the interaction between waves that meet |
| constructive interference | the interference that occurs when waves combine to make a wave with a larger amplitude |
| destructive interference | the interference that occurs when two waves combine to make a wave with a smaller amplitude |
| standing wave | a wave that appears to stand in one place, even though it is really two waves interfering as they pass through each other |
| node | a point of zero amplitude on a standing wave |
| antinode | a point of maximum amplitude on a standing wave |
| resonance | the increase in the amplitude of a vibration that occurs when external vibrations match an object's natural frequency |
| seismic wave | a wave produced by an earthquake |
| P wave | a longitudinal seismic wave; also called primary waves; move faster than other seismic waves; compress and expand the ground like a spring toy as they move through it |
| S wave | a transverse seismic wave; also called a secondary wave; shake the ground up and down and side to side as they move through it; move more slowly than P waves |
| surface wave | a combination of a longitudinal wave and transverse wave that travels along the surface of a medium; move more slowly than P waves or S waves; cause the most severe ground motions |
| tsunami | a huge surface wave on the ocean caused by an underwater earthquake |
| seismograph | an instrument used to detect and measure earthquake waves |
