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the old bushman’s waterfalls

the old bushman’s waterfalls. Example of rapid of French Guiana. Summary:. Fauna and flora of the waterfalls Two persons missing at the Old Bushman waterfalls Is the direction of rotation of a vortex influenced by latitude?. Fauna and flora of the waterfalls.

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the old bushman’s waterfalls

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  1. the old bushman’s waterfalls

  2. Example of rapid of French Guiana

  3. Summary: • Fauna and flora of the waterfalls • Two persons missing at the Old Bushman waterfalls • Is the direction of rotation of a vortex influenced by latitude?

  4. Fauna and flora of the waterfalls In the falls, the speed of the stream is quite high and water is more oxygenated.

  5. A rock fish A carp A periodontal

  6. A koumarou Salads koumarou

  7. Picture of the tendrils of a plant living in a fall

  8. Is the water of the falls much oxygenated? Materials: 3 beakers, shaken water, still water, oxygen meter probe. Experiment:

  9. Observation:In shaken water, the oxygen level is 12.18 mg / L.In still water, the oxygen level is 9.18 mg / L. The rate of oxygen increased of 75%. • Interpretation: When the water is shaken, the oxygen is more important than when water is still. • Conclusion: The flora and fauna of the falls are adapted to a very high rate of oxygen.

  10. Two persons missing at the Old Bushman waterfalls

  11. Beyond the falls Voltaire, at approximately 8,5 km upstream, an unsecured path gives access to other falls after several hours walking (about 4h), called the “Vieux Broussard“, the Old Bushman. Geographical situation of the falls

  12. Two persons missing at the Old Bushman waterfalls An accident happened on Thursday, November 2, 2006 to a group of hikers. Twins of 27 years drown in a vortex.

  13. Diagram of the siphon with the inactive vortex

  14. We did an experiment to see how the accident happened • Materials: Cutting water bottle of 5l connected to a pipe; a elastic, whose acts as a human body, having the same density : d=0.9. d = m body / m water where m is the mass volumetric and d is the density.

  15. Experiment :

  16. Observation : a vortex is created and carries the elastic away in the pipe. The elastic gets stuck in the pipe. • Interpretation : the two men were carried in the vortex. They were stuck in the siphon and died asphyxiated. • Conclusion : a vortex (also called whirlpool) can be very dangerous for humans.

  17. Operating diagram of the siphon

  18. Is the direction of rotation of a vortex influenced by latitude? Cyclone in the Southern Hemisphere

  19. Cyclone in the Northern Hemisphere

  20. To calculate Coriolis acceleration, a, we use the following formula : • With : w : angular speed of sidereal rotation of the Earth. Let us take : j : the number of seconds in a day. Let us take j ~86164 s. v = velocity of the water in motion. Let us take : v=1 m/s. φ=latitude of the place considered. Let us take : φ~480 • Numerical application: • Either 100 000 times less than the acceleration due to gravity (g = 9.81 m / s). • So the sink empties until the deviation due to the Coriolis force was done.

  21. Lexicon • Siphon: natural conduit swamped • A vortex: a circular or helical movement of the water in a stream • The Coriolis force: it is the centrifugal force due to Earth's rotation. It is a fictitious force because it exists only because the observer is in a rotating frame so that no force is exerted for an observer in an inertial frame. It exerted on all objects in motion, including the atmosphere and oceans.

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