The science of sound

A sunny afternoon for a practical demonstration of sound waves.

Ganges class were causing quite a royal racket in school the other day when they were investigating the effect of sound waves in science.
The afternoon began with a playground demonstration of how sound travels before the children were asked to figure out which equipment they would need for the practical experiment, and which they could discard, from a number of different resources, with a few deliberate red herrings in there for good measure.

Now which of these will we need?

First you cut off the neck of the balloon.

It is quite a tricky job to stretch it over the glass.

We've done it!

After some puzzling they agreed that they would need the scissors, the glass and the balloon. Once they had things in place, it started to get rather noisy as the children tried to make the salt and sugar move by humming, bonging the cow bells and strumming the ukeleles and guitars.

Everyone was pleased to see how the sound waves caused the balloon skin to vibrate and scatter the salt and sugar all over the desks. After all, if you can't make a bit of a mess in the name of science, when can you?