8th Grade PS Unit 8 & 9: Waves

14 flashcards · Physics · by Samvid Konchada

1. A substance through which a wave moves. i.e. water for waves in the ocean

   Medium

2. The highest point, or peak, of a wave. i.e. the highest point of a tsunami

   Crest

3. The lowest point, or valley, of a wave i.e. lowest point of a ocean wave

   Trough

4. A type of wave in which the disturbance moves in the same direction that the wave travels. i.e. sound wave

   Longitudinal Wave

5. A type of wave in which the disturbance moves at right angles, or perpendicular, to the direction in which the wave travels. i.e. light waves

   Transverse Wave

6. The distance from one wave crest to the next crest; the distance from any part of one wave to the identical part of the next wave. i.e. wavelength of audible sound range from about 17 mm to 17 m

   Wavelength

7. The number of waves that pass a fixed point in a given amount of time, usually one second; the number of cycles per unit time. i.e. the frequency of violet light is greater than the frequency of red light

   Frequency

8. The maximum distance that a disturbance causes a medium to move from its rest position; the distance between a crest or trough of a wave and line through the center of a wave. i.e. The amplitude of a wave is its height above the mean level.

   Amplitude

9. The bouncing back of a wave after it strikes a barrier. i.e. light reflects of a mirror

   Reflection

10. The bending of a wave as it crosses the boundary between two mediums at an angle other than 90 degrees. i.e. light refracts when it goes through a prism

    Refraction

11. The spreading out of waves as they pass through an opening or around the edges of an obstacle. i.e. Sound waves can diffract around objects, which is why one can still hear someone calling even when hiding behind a tree.

    Diffraction

12. The effective increase in the overall amplitude of a resultant wave when the peaks of two or more constituent waves overlap and amplify each other. i.e. When two stones are dropped into a pool of water, waves spread out from each source, and interference occurs where they overlap. Constructive interference results where the crest of one coincides with the crest of the other.

    Constructive Interference

13. Destructive Interference occurs when the maxima of two waves are 180 degrees out of phase. i.e. two sound waves destructively interfere and this cancel each other out

    Destructive Interference

14. The change in perceived pitch that occurs when the source or the one who hears the sound is moving. i.e. ambulance siren

    Doppler Effect