Potential Energy
Energy and Thermal Physics

Simple Siphon

Enrichment Activity for 5-11 11-14


What you need

  • A bendy straw
  • Water
  • Two small flat bowls
  • Food colouring

Instructions

  1. Fill one bowl with water and a little food colouring
  2. Half fill the second bowl
  3. Submerge the straw in water, making sure you get rid of any air bubbles, and tightly pinch the ends of the straw before you pull it out
  4. Hold the straw with one end in each bowl, and release the ends when they're under the water

Results and Explanation

The water in the bowl with the higher water level is under greater pressure, and so water moves through the straw to the lower level.

IOP DOMAINS Physics CPD programme

Energy CPD videos

Our new set of videos gives teachers and coaches of physics a preview of the training we offer ahead of this term's live support sessions.

Find out more