Measuring the Speed of Sound (Starter Pistol Lab)

A box containing a flood light and a car horn were placed 400 meters away form an observer. The flood light and the horn were simultaneously triggered. The observers measured the time delay between seeing the light and hearing the sound.

The original version of this lab had a teacher shooting a track and field starter pistol and the students measuring the time delay between seeing the smoke and hearing the sound of the starter pistol.

Air temperature on the day this test was performed: 12 degrees Celsius.
Distance to apparatus: 400 m

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[MrChrismdd]

Nice idea, much better than clapper boards or the echo method and much safer than bangers or shotguns. Although my all time favourite is igniting balloons filled with the correct mixture of hydrogen and oxygen. Will definitely try your method.