The wave equation

• What is wave speed?

  The speed at which the wave moves through the medium (the speed at which energy is transferred.
• What is the wave speed equation?

  Wave speed (m/s) = frequency (Hz) x wavelength (m)
• What method can be used to measure the speed of sound waves in air?

  Separate two people by a distance of 500 metres. Person A holds the object creating the sound and person B holds a timer. Person B starts timing when they see the the object move to create the sound. Person B stops timing when they hear the sound the object makes. Calculate the speed of sound waves by dividing the distance travelled by the time taken.
• What are the issues with the method used to calculate wave speed?

  Every persons reaction time is different.

  It takes a fraction of a second between seeing the object move to create the sound and starting the timer.

  It also takes a fraction of a second between hearing the sound and stopping the timer.
• How do we reduce the issues that arise when using this method to calculate wave speed?

  Use a large number of observers with timers, take all of their results and discard any that are anomalous. We then calculate a mean value.

  Increase the distance between person A and B because the time between seeing the object make the noise and hearing it is very short meaning it is difficult to push the button on the timer at the correct moment.