Exploring Interference of Waves

The first experiment involves a version of the two-slit experiment of Young. We will use something that we know is a wave. It's a wave drawn on a piece of plastic or paper.

To do the experiment:

1. Print TWO copies of the graphic in the accompanying window.
2. If possible photocopy the graphics on to overhead transparencies. This step is optional.
3. Cut the paper or overhead transparencies into strips so that each strip has a single wave on it.
4. Select two identical wave-forms (the amplitude, and wavelengths should be the same).
5. Take a blank piece of letter paper and use a pencil to make the marks on it as illustrated below. The dots should be about 5 cm apart.
   
6. Place a straight pin in one end of each wave and secure the waves on the dots.
7. On the paper, mark with an X locations where the addition of the two waves is a maximum (constructive interference).
8. Place zeros where the two waves cancel each other (destructive interference).

Below is a picture of the setup if you are confused.

[insert picture - Sarah]

Try waves with different amplitudes or wavelengths for this experiment and compare your results.

How does the distance between zeros depend on wavelength and amplitude?