Measuring the Speed of Sound - Experiment
Physics: Edexcel IGCSE, topic 3.4.6
Measuring the Speed of Sound - Experiment
Echoes can be used to measure the speed of sound.
Speed of sound - echo
- Two people stand a measured distance from a tall vertical wall. This distance should ideally be about 100m.
- The first person bangs two wooden blocks together to make a sharp sound, and repeats this every time the echo is heard.
Speed of sound - echo
- Starting counting from zero, the second person uses a stopwatch (timer) to measure the time taken for a number of claps – 50 or 100.
- In the time between two successive claps, the sound travels to the wall and back.
- The speed of sound can be calculated from the following relationship:
- speed of sound = distance to wall × 2 × number of claps (N) ÷ time taken for N claps.
Test yourself on Measuring the Speed of Sound - Experiment
In the echo experiment, if the distance to the wall is measured as larger than it really is, what happens to the calculated speed of sound?
A pupil stands 100 m from a wall and makes a loud sound. In the time between making the sound and hearing the echo, how far has the sound wave travelled in total?