A. Materials needed:
- A glass filled with water
- X3 Bent straws,
- A pair of scissors
- Fix the three bent straws to form a near M-shpe as shown on the top right corner of this flyer.
- Ensure that the right side of the bend is higher than the bend on the left side.
- Tape the joints with a cellophane tape to make airtight. Now you have a siphon!
- Fully immerse the shorter end of the siphon into a glass filled with water. This is the reservoir.
- Insert the other open end of the siphon into another container.
- Observe what happens!
SO HOW DOES THE SELF-STARTING SIPHON WORK?
Water flows automatically from the reservoir to the other conatiner due mainly to atmospheric pressure and cohesion. Atmospheric presssure initially forces some water through the submerged end of the straw. This enables the water to overcome gravity and rises through the straw. The cohesion (force of attraction between molecules of the same kind) among water molecules ensures continous flow to sustain the process.
TAKING IT FURTHER
Try this experiment with a U-shaped tube. Does it work as effectively? What do you think is the effect of tube diameter on the rate of water flow? Set up an experiment to confirm your hypothesis (speculation).
Share your results with us @eduspots