**Interference Patterns & Wavelength
Obj: **Study constructive and destructive interference to
determine wavelength.

**Methods**
**& Analysis**

1.
Set up the ripple tank with 2 wave point sources
approximately 4 cm apart.

2.
Carefully sketch the pattern on your data sheet, showing
the constructive and destructive interference areas.
Draw a line down the **center of each antinode**; label
as n = 0
(center),1,2,3, etc. as discussed in class.

3. Label all *nodes*
and *antinodes*.

4. Mark a single
point on an antinode; measure the distance (d) back to each point
source. The *DIFFERENCE*,
d_{2} - d_{1}, is a whole number integer of one **λ**.

5. Find:
**λ** = d_{2} - d_{1} / n where n = 1,2,3 from which you measured.

6. Rotate the point
sources out of the water. Using
only the long board as the wave generator, place two barriers in
line with each other about 10 cm apart.
Roughly sketch the diffraction pattern showing how much
diffraction is occurring.

7.
Repeat for the barriers #1
cm apart. Draw a conclusion about the amount of barrier
separation and the amount of diffraction.

8.
Explain what is causing the antinodes and nodes (be
specific!). Why does
diffraction occur at a boundary.

Back to the Brockport High School Science Department