Posted: 1/3/2010 1:29:19 PM EDT
My son is in the fifth grade. Anyone with some cool suggestions for a science fair project? Home-made bombs do not apply. 
What does the hive think? |
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Crystal radios are always cool. They are fairly easy to construct, too. The "crystal," which originally was a Galena (read: lead oxide) crystal, can be replaced with a number of common items. Nowadays they usually use a fairly common diode, but in the past, some people have used razor blades. (There was a big debate once upon a time about what brands of blades were best.) Have your son demonstrate that the diode "decodes*" the radio wave and turns it into sound! Then have him show that various common materials will also "decode*" the radio wave. (Hint: they are usually oxides of some metal.)
Also, have him demonstrate history, and the small size, of a crystal radio. These were frequently used by people behind Nazi German lines, and by people behind the Iron Curtain, because radios were forbidden: the despots didn't want the peons hearing REAL news! Of course, he also needs to post an AAR! Best of luck to him! *The actual term is "detect.**" **Someone will stop and correct me; that's OK as my brain is rusty, and rather slow this morning due to excessive alcohol intake. |
| the radio sounds cool, but he won't be at the table to demonstrate... these days they are made up of photos... kind of like a dinner pic thread. Most entries are about how cabbage water can detect Ph. or growing rock crystals, but I was trying to come up with something different (and it's been over 35 years since I was in the 5th grade and my brains rusty) LOL |
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Have him do an experiment testing the life of batteries. He can wire everything up himself, with crap you buy at Radio Shack. Put a couple of AA's in series, then a 3v lamp, some wires, a timer/stopwatch. Simple, cheap, and teaches him a little of electricity.
And you get the added benefit of knowing which batteries last longest 
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| I second the spud-gun. A science fair project should pose a question and then answer it, not simply display something, so you could choose something in particular to measure, such as differing distances the spud will fly based on the angle or trajectory of your set-up. There must be a question, a way to measure different outcomes, and a clear solution. Otherwise, everyone would just "show something cool" like the typical volcano eruption. |
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Google Atomic Boy Scout |
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Quoted:
I second the spud-gun. A science fair project should pose a question and then answer it, not simply display something, so you could choose something in particular to measure, such as differing distances the spud will fly based on the angle or trajectory of your set-up. There must be a question, a way to measure different outcomes, and a clear solution. Otherwise, everyone would just "show something cool" like the typical volcano eruption. Hypothesis: Different types of potatoes have different densities. Test: Shoot standardized slugs of potatoes out of a potato gun, and track their ballistic properties (velocity, drop, and accuracy). |
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Quoted:
Have him do an experiment testing the life of batteries. He can wire everything up himself, with crap you buy at Radio Shack. Put a couple of AA's in series, then a 3v lamp, some wires, a timer/stopwatch. Simple, cheap, and teaches him a little of electricity. And you get the added benefit of knowing which batteries last longest My oldest daughter is in 4th grade and has to do a science project (due in another week). She chose to do the battery life experiment using AA batteries. We were able to scrounge up 13 different brands of alkaline AA batteries from a multitude of stores. We bought a pack of mini screw lamp bases and a pack of #112 flashlight lamps for them from Radio Shack. They were cheap, ~$4 total. I soldered a 12" wire on to each terminal of a lamp base. We also bought a cheap clock that runs on a single AA battery from Walmart. For the experiment my daughter sets the clock to 12:00 then installs a battery then wedges an end of each wire on either side of the battery. So basically the lamp creates a load and the clock acts as a timer as we end each experiment when the clock stops moving. With this setup we can let it run without having to be there when it stops to record the time. Each battery has been running anywhere from 4 to 6 hours. So far Energizer & Duracell last the longest (not by much) but the cheapo Sunbeam brand alkalines from the dollar store are a much better deal (4 for $1 & last almost as long).
ETA: The science project rules & guidelines from her school were ridiculously limiting which is one reason why she chose the battery experiment. |
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A buddy and I built a TEA Laser in high school. They are pretty simple devices which can be made with things you find at Lowes with the exception of the high voltage supply. (EDIT: 5th grade, maybe a bit too much) http://www.technology.niagarac.on.ca/people/mcsele/lasers/LasersTEA.htm When in middle school my dad and I built a hovercraft using particle board, a tire inner tube (free at truckstop) and a vacuum cleaner motor.There was no propulsion, but I was the only one able to ride my project! I was an electrical engineering major, so my interests lie there, however it should be pretty easy to build a simple wire motor. Trebuchet if you are handy in the building stuff department. Experiment with different counter-weights or sling lengths. |
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Make a Fire Piston
Demonstrate how simply compressing air can generate enough heat to ignite a piece of tinder. It's the technology that led to the creation of the diesel engine... |
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A STIRLING ENGINE can be described in 4 to 6 frames. Then he can show some practical examples of them in operation.
New Mexico power generation |
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Radio Shack or for those in the now: The Shack has a nice little decibel meter to test whether commercials are really louder than the regular programming. A good write up and pics taken from the shack site and a graph or spreadsheet will get the kid a good grade and a little knowledge. hint; yep they are |
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If its anything like the science fairs my son's have done, this needs to be an actual experiment (present a hypothesis then test it), not just a "science gizmo". One 5th grade experiment we did was to test if talking on a cellphone impairs driving. We did this by having everyone in the family drive a standard car around the same racetrack in an XBox 360 car street racing game. The test metric was the speed to complete the course (crashes eat up time). Each participant drove three times normally (the control), three times while "talking" with a handheld phone ("talking" meant conversing with other family members in the room), and three times while "talking" with a hands-free kit. The order of the runs was randomized to reduce the influence of experience. We were able to gather all the data in one evening, then use statistics to determine if driving with a phone in your hand is more dangerous.
In our testing, driving with the phone in your hand was significantly more dangerous than the control, while driving with a hands-free kit was not significantly more dangerous than the control (times were longer, but the difference was not not statistically significant). One last suggestion (you will thank me for this)... NEVER WORK WITH ANIMALS. My son chose an experiment with ants for his 8th grade science fair, and trying to work with ants was a giant clusterfuck  .
HTH |
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was thinking
Solar = solar panel to maybee a stove burner Water= purification test , boiled , filter Wood= maybee floating test, thickness, dense, tempature. My brother made a sun light oven to cook a hot dog. Wood painted black, tin foil inside and a magnifier top sheet. The wood got so hot there was smoke ! Maybee line with extra foil , He got an A+. Sun light magnified in to heating source I think was the goal ! |
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Go google up "Gratzel Cell." It's a second generation hybrid organic/inorganic solar cell, also called a "dye-sensitized solar cell." You can actually build them pretty easily if you get ahold of some powdered alumina and some iodine (it's not hard). The neat part is that the dye can come from pretty much any colored fruit or berry. You could make up several cells, and test which fruit juice produces the best solar cells. |