Enrichment Activity for 5-11 11-14
- Level Elementary
What you need
- A plastic drinks bottle
- Fill the bottle with water so it is very nearly full
- Put the lid on tightly and throw the bottle in the air. Watch it carefully on the way up and down
- The air inside the bottle will form a spherical bubble as it’s falling!
Results and Explanation
When the bottle is in free-fall, surface tension forces the air into a bubble with the least possible surface area – a sphere. In space, the same effect can be seen with liquid drops in air.