Thunder and Lightning

Did you know that it is possible to measure the distance you are from an electrical storm, you simply count the time that elapses from when you see the lightning flash until you hear the thunder.

You can measure the elapsed time using a stop watch or you can count the seconds like so:

To measure the elapsed time you start your count when you see the lightning flash and stop counting when you hear the thunder.You then you write down the last red number that you said - which is your elapsed time.

To calculate the distance you are from the electrical storm you simply divide the elapsed time by three. This gives you a distance in kilometres between you and the storm.

For example:
The elapsed time from when you saw the lightning to when you heard the thunder was 6 seconds (six, one thousand)
6 divided by 3 is 2, so you are 2km from the electrical storm.

In the following exercise try and calculate your distance fromthe following six electrical storm simulations.
Use the recordsheet provided to record your results.

To view the simulation you will need Flash 4 installed on your computer.

Click here to go to the simulation


Created by Andrew Cuthbertson
Last Updated June 1, 2000


The worksheet is available here as a PDF file.


You will need Acrobat Reader to view the worksheet. Follow the link to download it.

If you can see the animation below and can hear the sound when you move your mouse over it, then you have Flash 4 installed. If not, you will need to install Flash 4 to view the simulation.

Click here to download the FREE
Flash Player