- A. General Materials & Mathematics
- B. Statics
- C. Kinematics & Dynamics
- D. Rotational Mechanics
- E. Gravitation & Astronomy
- F. Fluid Mechanics
- G. Vibrations & Mechanical Waves
- H. Sound
- I. Thermodynamics
- J. Electrostatics & Magnetostatics
- K. Electromagnetic Principles
- L. Geometrical Optics
- M. Wave Optics
- N. Spectra & Color
- O. Vision
- P. Modern Physics
H1-25. Speed Of Sound Between Two Microphones
To measure the speed of sound by determining the travel time of a pulse between two microphones.
Oscillator, small speaker, two microphones with holders on optical rail, mixer amplifier, and oscilloscope.
A loudspeaker sends pulses past the two microphones, and the oscilloscope displays the pulses on its time axis. The oscillator is run at 40 Hz to produce well-separated pulses. The speed of sound is the distance between the two microphones divided by the time delay read from the oscilloscope. If the scope is set to 0.2ms/div, the math is simple if you move the microphone so that the two pulses are 5 cm or 1 ms apart.