Measuring the Speed of Sound

Broadfield Method

• Burst a hydrogen-oxygen filled balloon at one end of Broadfield lawn.
• Pupils start stopwatches when the balloon disappears.
• Pupils stop stopwatches when sound reaches them.

N.B. Given that the speed of sound is approximately 340m/s and that human reaction time is about 0.2s there is no way that this experiment can possibly give an accurate value.

Clapper Method

• No idea. I'm working on it. It almost certainly suffers from the same reaction time problem as referenced above.

Method that Actually Works

• Use fast timer connected to two microphones.
• Connect first microphone to start trigger and second microphone to stop trigger.
• Use short/sharp sound to start and stop timer.