Equations
Intensity of a point source
Waves · id sound_intensity
I = \frac{P}{4 \pi r^2}
| Symbol | Quantity | Unit | Meaning | Usual range |
|---|---|---|---|---|
I | intensity | W/m^2 | Power per unit area | 0 to 1e+09 |
P | source power | W | Power emitted by the source | 0 to 1e+09 |
r | distance | m | Distance from the source | 0.01 to 1e+07 |
Assumptions
- Source radiates equally in all directions
- No absorption or reflection
Valid when
- No extra conditions.
Found by
Questions with these words retrieve this equation: intensity, sound, loudness, speaker, inverse square, light bulb, distance.
Source
OpenStax University Physics Volume 1, Chapter 17 (reference; entry written by the project). License: MIT. Entry confidence: 0.98.