## Inverse Square Law (of Sound Waves)

Author(s): Brandon Duran, Craig Didden and Laurie Aiello
Probeware / Instrumentation
SED 695B; Fall 2005

Research Question:

or

How does sound level change with distance?

Physics:

Waves
4. Waves have characteristic properties that do not depend on the type of wave. As a basis for understanding this concept:

 a. Students know waves carry energy from one place to another. d. Students know sound is a longitudinal wave whose speed depends on the properties of the medium in which it propagates. f. Students know how to identify the characteristic properties of waves: interference (beats), diffraction, refraction, Doppler effect, and polarization.
Independent variable
Dependent variables
Controls
Series

distance

Sound Level

None Distance vs. Sound Level
Materials
Procedures
• Computer with Wave Generator
• Two speakers.
• Sound Intensity Meter (probeware).
1. Set up a speaker with a given tone, with a set volume.
2. Measure the sound level at increasing distances from the speaker.
3. Graph and analyze your data.
Distance from Speaker (cm) Sound Level (dBC)
0

5

10

15

20

25

30

Blank Data Table.
Distance from Speaker (cm) Sound Level (dBC)
0
107.32
5
98.58
10
93.13
15
91.96
20
91.05
25
90.65
Sample Data
See Sample Graph Here