2006-12-03 12:25:58 · 7 answers · asked by Anonymous in Education & Reference ➔ Homework Help
the rainbow, alligators, solar-powered cars, conducting electricity, tsunamis, black holes, forensics
2006-12-03 12:30:52 · answer #1 · answered by Scorpius59 7 · 1⤊ 0⤋
this is one i used to win first place back in the day...
water purification:
first i had a little history, talking about famous explorers on ships long ago who would run out of water while traveling the ocean "water water everywhere and not a drop to drink" and how they ended up drinking their own urine to keep hydrated (ew, but true!)
then i had the experiment:
mix up a batch of salt and water, put it in a big glass bowl, cover the top with saran wrap and put a small rock in the center of the wrap to weigh it down.
then put it out in the sun. the water will evaporate, hit the saran wrap, and drip back down into the bowl, leaving all of the salt at the bottom, and the pure water on top!
this is the point where you talk about the effects of heat on liquids turning to gas and back again, and about how the heavier salt separates from the soulution (go to the link below for technical terms)
finish up by going back to the explorers and how they should have used this method with a piece of glass instead of saran wrap to purify seawater to survive.
p.s. this method also works on stuff like ditch water. it doesn't get rid of germs, but does separate out the dirt.
2006-12-03 21:34:09 · answer #2 · answered by jumpoutjane 3 · 0⤊ 0⤋
I recently went to a convention where this man showed us the dangers of bateries.
You know how when they are dead you just throw them in the trash? Well they are probably not dead.
(now be careful) Touch the baterie to some steel wool. It will catch flame. Warn the people to tape their bateries before throwing them away!
2006-12-03 20:35:52 · answer #3 · answered by Wishful Thinking 1 · 0⤊ 0⤋
Mentos and Diet Coke:
http://www.youtube.com/watch?v=9vk4_2xboOE
2006-12-03 20:34:29 · answer #4 · answered by Anonymous · 0⤊ 0⤋
u can do it about shampoo, which 1 works best and has the most bubbles or diapers which 1 absorbs water and maybe some other liquids best. my friends did these, seriously, and they almost won. (last year)
2006-12-03 20:35:47 · answer #5 · answered by J 5 · 0⤊ 0⤋
Do something that in the past years, your school judges had never seen. Try something unusual, just as long as it fits your curricilum.
2006-12-03 20:36:25 · answer #6 · answered by hellomotto89 2 · 1⤊ 0⤋
blow some stuff up! exciting is good, catch there eye with whatever you do! (get supervisison)
2006-12-03 20:29:03 · answer #7 · answered by PJ 2 · 0⤊ 0⤋