Enrichment Activity for 5-11 11-14
What you need
- Two large plastic bottles
- A washer
- Duct tape
- Food colouring
- Fill one bottle two-thirds full with coloured water Turn the other upside down, put a washer between them and tape the joint firmly
- Turn them upside down, let the water flow normally, then swirl the bottles around vigorously
Results and Explanation
When you swirl the water, it forms a vortex like a tornado and flows much faster into the lower bottle.
Air from the lower bottle rushes to the top through a hole in the middle of the vortex as the fast-flowing water drains rapidly at the edges.