Waves 2

Waves 2

1. Plane mirror- a mirror that is flat, no curve

2. refraction direction- if a wave speeds up, the direction hanges away from the normal (angle gets bigger if speed is bigger)

3. the big bang theory- if the galaxies are moving apart, then in the past they were closer together, 14 billion years ago they were all in the same spot

4. volume- for a sound wave, the amplitude has alternative names

5. wave- when energy moves

6. pitch- for a sound wave the frequency has an alternative name

7. transverse- oscillations across the wave direction

   • longitudinal- oscillations along the wave direction

8. human hearing range- 25Hz to 25000Hz

9. red-shift- the doppler effect, applied to light from distant galaxies whose wavelength lengthens as they move away from us

10. ultrasound- sound waves with a frequency too high for us to hear, above 20000Hz

11. reflection- when a wave 'bounces off' a surface; the angle from the normal stays the same

12. normal- a line perpendicular to a surface, to measure wave angles from

13. refraction- the bending path of a wave when the speed changes