1. Science of Sound and Music

2. How can we measure the speed of something?

3. Distance ÷ Time = Speed

4. How can we measure the speed of something? Distance ÷ Time = Speed Some examples of “speed”… Snail:2 inches per hour Car:55 miles per hour Light:300,000,000 meters per second

5. How can we measure the speed of something? Distance ÷ Time = Speed In 1998 Florence Griffith-Joyner set the World Record in the women’s 100 meters by running it in 10.49 seconds. What was her speed?

6. How can we measure the speed of something? Distance ÷ Time = Speed In 1998 Florence Griffith-Joyner set the World Record in the women’s 100 meters by running it in 10.49 seconds. What was her speed? 100 meters ÷ 10.49 seconds = 9.53 meters per second

7. Temp (deg C)Speed (m/s) 20343.2 21343.78 22344.36 23344.94 24345.52 25346.1 The speed of sound varies slightly with temperature…..

8. Temp (deg C)Speed (m/s) 20343.2 21343.78 22344.36 23344.94 24345.52 25346.1 Distance ÷ Time = Speed The speed of sound varies slightly with temperature…..

9. Setup and procedure Connect microphone preamps to “Line In” jack on PC via RCA to 1/8” stereo cable Open Audacity –Under the “Edit > Preferences” menu, set Channels to 2 (Stereo) Set PC to record from “Line In” –Open “Volume Control” Press record on Audacity Make a loud sharp noise (eg. snap fingers) Press stop on Audacity

10. General notes on the experiment The microphone converts sound to electricity. The amplifier is used to increase the microphone's low output voltage to a stronger level that can be recorded by the PC. The PC is capable of recording in stereo, which means it can simultaneously record the signals from two different microphones.

11. General notes on the experiment Sound from a source will travel across the room and reach the microphones at different times. The recorded audio can be analyzed on the PC to determine the amount of time it took for sound to pass from the location of mic 1 to mic 2. The distance between the microphones can be measured with a ruler, tape measure, etc. The speed of sound can be calculated by dividing the distance by the time.

12. Microphones placed 143 ½ inches apart  345.3 m/s Example screen shot