How To
Measure the speed of Sound?
The complete experiment can be found in the Physics With Vernier book, experiment 33.
Brief
Measuring the speed of sound in a standard lab is a challenge as sound waves travel very fast. One method that is commonly used is the time a echo over a distance of 250m. Staring the stop watch when the noise is made and stopping when its returned. This time and distance could be then used to calculate the speed of sound.
To most they will not have the space to do this. We could scale the distance down to a 50cm piece of pipe (total distance 1m), the issue we then would have is we would be unable to time this very well using a stop watch. This is where a fast timing system such a datalogger is needed. Using a Microphone at the open end of the pipe. You can collect data of the noise at the start and the echo at the end. From this graph you can accurately work out the time it took the sound to travel over the total distance and thus the speed on sound.
An extension to this would be to also measure the temperature of the air to account for this adjustment.
Objectives
- Measure how long it takes sound to travel down and back in a long tube.
- Determine the speed of sound.
- Compare the speed of sound in air to the accepted value
Sensors and Equipment
Additional Requirements
You may also need an interface and software for data collection.