Speed of Sound Measurement
Determination of the speed of sound in air using acoustic resonance in a variable-length column.
Project Overview
This experiment utilizes the phenomenon of acoustic resonance to measure the speed of sound $v$ in air. By adjusting the length of an air column driven by a tuning fork of known frequency $f$, standing waves are generated at specific harmonic lengths.
The relationship $v = f\lambda$ allows for the calculation of wave speed by identifying the nodes and antinodes of the standing wave pressure distribution.
Key Concepts Investigated
Standing Wave Resonance
Identified the fundamental frequency and higher harmonics in an open-closed pipe system, satisfying the boundary condition $L = \frac{n\lambda}{4}$ (for odd $n$).
End Correction
Accounted for the "end correction" factor—the fact that the pressure antinode forms slightly outside the open end of the tube—to improve measurement accuracy.
Temperature Dependence
Compared experimental results with the theoretical speed of sound, which varies with temperature as $v \approx 331 + 0.6T$ m/s.
Full Documentation
The report includes data on harmonic lengths, resonance calculations, and temperature adjustments.