1. Chs. 17 & 18 - Waves III. Wave Behaviors Reflection Refraction
Diffraction
Interference

2. A. Reflection Reflection when a wave strikes an object and bounces off
Normal
Reflection
when a wave strikes an object and bounces off
incident beam
reflected beam

3. A. Reflection Inversion
A transverse wave traveling to a fixed end or colliding with a denser medium will flip on its way back

4. A. Reflection
Reflecting light in a mirror
A type of transverse wave

5. Ultrasound Medical Imaging “Sound Navigation Ranging”
A. Reflection
Ultrasonic waves
Ultrasound Medical Imaging
SONAR
“Sound Navigation Ranging”

6. A. Reflection
RADAR
Radio detection and ranging

7. Anechoic chamber - designed to eliminate reverberation.
A. Reflection
Reverberation
echo effect produced by the reflection of sound
Anechoic chamber - designed to eliminate reverberation.

8. B. Refraction Refraction
bending of waves when passing from one medium to another
caused by a change in speed
slower (more dense)  light bends toward the normal
SLOWER
FASTER
faster (less dense)  light bends away from the normal

9. B. Refraction Surface waves (ocean waves)
Do not travel throughout the entire medium
Refracted as the water depth changes
Bends toward the shore

10. B. Refraction Refraction of light depends on…
speed of light in the medium
wavelength of the light - shorter wavelengths (blue) bend more

11. B. Refraction
Example:
View explanation.

12. B. Refraction
Example:
The “broken” pencil

13. C. Diffraction Diffraction bending of waves around a barrier
Smaller opening = more diffraction

14. C. Diffraction
longer wavelengths (red, for light) bend more, especially when the opening is small - opposite of refraction

15. D. Interference Interference – occurs when 2 or more waves overlap
constructive interference  2 or more waves combine to produce a wave with larger displacement
Constructive - louder

16. D. Interference
destructive interference  2 or more waves combine to produce a wave with smaller displacement
Destructive - softer

17. D. Interference
For light – brighter portions show constructive interference, darker show destructive interference

18. E. Cool Applications! Fiber Optics Total Internal Reflection
when all light is reflected back into the denser medium

19. E. Cool Applications! The “Broken Pencil” refraction
View animation and explanation of the “Broken Pencil.”

20. E. Cool Applications!
Rainbows
refraction-reflection-refraction

21. E. Cool Applications! Diffraction Gratings
glass or plastic made up of many tiny parallel slits
may also be reflective
spectroscopes, reflective rainbow stickers, CD surfaces

22. E. Cool Applications! Thin Films - Bubbles & Oil Slicks
interference results from double reflection

23. E. Cool Applications! Blue Sky & Red Sunsets
Molecules in atmosphere scatter light rays.
NOON
less atmosphere
less scattering
blue sky, yellow sun
Shorter wavelengths (blue, violet) are scattered more easily.
SUNSET
more atmosphere
more scattering
orange-red sky & sun

24. E. Cool Applications! Resonance special case of forced vibration
object is induced to vibrate at its natural frequency