As part of our 'Titanic' topic, P7 will be doing a series of experiments.
On Friday, we did an experiment looking at BOUYANCY.
To make sure it was a Fair Test, each group was provided with exactly the same items.
Raisins were dropped into a cup of still water and a cup of sparkling water.
In both cases, the raisins sank to the bottom as they are more DENSE than water.
Although the raisins remained at the bottom in the still water, after a short period of time, they started to rise and fall in the sparkling water.
What caused this to happen? The weight (density) of the raisins hadn't changed. We also hadn't changed their shape.
After much discussion we decided it had something to do with the bubbles (air) in the sparkling water.
The air bubbles attach to the crevices in the raisins giving them buoyancy. This allows them to raise to the surface. However, once they reach the surface, the bubbles pop and the raisins return to the bottom and the process begins again.
This gives the impression that the raisins are dancing!
It isn't magic, it's SCIENCE.
Menu
