1. Ripple Tank Summary

2. Why Ripple Tanks :
Real waves (sound, light, radiation) are difficult to observe
Properties of waves should be independent of the type of wave
Water waves (which are easy to see) provide a useful analogy for other types of waves

3. Wave Properties Transmission Reflection Refraction Diffraction
Interference

4. Transmission
The traveling of a wave through a medium away from a vibrating source

5. Transmission
The wavelength of the generated wave does not change as it travels the length of the ripple tank
The speed of the wave remains a constant

6. Transmission
If the medium doesn’t change the speed must remain constant
A change in the frequency must result in a change in the wavelength
An increase in the frequency causes a shortening of the wavelength

7. Reflection
The changing direction of a wave upon impact with a barrier or object

8. Reflection
The speed of the wave, frequency and wavelength remains unchanged after reflection
Only the direction of the wave changes

9. Reflection
The direction of the wave changes such that the angle of incidence is equal to the angle of reflection

10. Refraction
Refraction is the bending of a wave as it passes from one type of medium into another type of medium

11. Refraction
As the surface waves travel from a deep to shallow environment the waves will bend and decrease in wavelength.

12. Refraction
Since the frequency of the waves can not change and the wavelength decreases, the speed of the wave as it travels from a deep section to a shallow section must decrease as well. This causes the waves to “pile up” on one another.
Tsunami

13. Refraction
This bending of the wave and the resultant change in speed has environmental implications!

14. Diffraction
The bending of a wave as it either passes by a barrier / object OR the spreading out of a wave as it passes through an opening

15. Diffraction
Longer wavelengths diffract easier around a barrier compared to shorter wavelengths
This is seen in the difference between light (a short wavelength) and sound (a long wavelength)

16. Diffraction
Waves can also diffract (bend) as they pass through an opening
Maximum diffraction occurs when the width of the slit is close to the wavelength of the energy

17. Diffraction
Diffraction is often used in creating wave breaks to help dissipate the incoming energy of the wave

18. Interference
The total disturbance within a medium when more than one wave is present

19. Interference The amplitudes of the waves will add together as vectors.
A crest plus a crest forms a much larger crest
A trough plus a trough form a deeper trough

20. Interference
If a crest and crest (trough and trough) add together we end up with constructive interference

21. Interference
If a crest adds to a trough (or trough to a crest) we end up with destructive interference

22. Interference
In most cases we end up with partial interference creating a beat.

23. Interference
Many objects display an interference pattern (such as electrons)