We woke up to a extremely humid day today and the news that the North QLD cyclone Yasi was upgraded to a cat 5. Let us hope it spontaneously combusts and causes little damage and destruction, as QLD has had a battering of late.
The cyclone does however provide a good opportunity to answer questions on cyclones and discuss weather in general today.
We felt the difference between outside in the high humidity where we were not cooling off, to inside where we had the aircon on. Our skin could release water and sweat in the dryer air, therefore we could cool down.
We discovered how a cyclone is formed after doing a search on the web (there are plenty of weather sites for kids). Did you know in the Northern Hemisphere Hurricanes flow anticlockwise and in the South cyclones flow in a clockwise direction.
We heard alot about air pressure in our search for information, so we did this experiment (from the Australian BOM website) to exemplify the force that air can have. We also read about ways of measuring air pressure.
You basically fill a plastic bottle one third with boiling water, put the lid on and stick it in ice and cold water, within seconds it starts to become pressurised.
It is a very quick experiment, good for younger children to watch the bottle get sucked in from within.
* Weather book by Discoveries David Ellyard. Find it at QBD.