Does the Amount Matter?
In the ice melting experiment, you learned about variables: things you change to see what happens. Let us change a variable in our sound experiment!
Variable: How much rice is in the bottle?
Fill three bottles with different amounts of rice:
- Bottle 1: Just a little rice at the bottom
- Bottle 2: Half full of rice
- Bottle 3: All the way full of rice
Predict: which one will be the loudest? Which will have the highest pitch?
Shake them and listen! The half-full bottle is usually the loudest because the rice has room to move and bounce around. The full bottle is quieter because the rice is packed tight and cannot move much. The nearly empty bottle has a rattly sound but is not very loud.
This is an important discovery: having more material does not always mean more sound!