Science fair project?
please give me some ideas
i want to make a device/working model that has some optical or mechanical or electronic application
the device should generate electricity on its own using solar or wing or any other eco-friendly source
please send in some innovative ideas
best one gets 10 points
the theme of the fair is science and environment
- David DLv 71 decade agoBest Answer
Here is the project… This will blow peoples minds.
Show how much money you save by switching to CFLs (Compact Fluorescent Lights).
Get a cardboard box, about one and a half feet cube, and put inside it a light fixture and a series of really big resistors. These resistors must be capable of about 100W dissipation. Get a precision thermometer – ideally one that can measure the inside of the box but be read on the outside of the box.
Choose and install an incandescent light bulb of a wattage so that after about 2 to 3 hours (or more) the temperature inside the box is about 100 degrees F. Once the temperature has stabilized hook up enough resistors and power them up so that the temperature goes up to about 120F. Calculate the total power used – light bulb and resistor power.
Now replace the incandescent light bulb with a CFL that puts out the same lumens (it should be about 1/3 the wattage). Now increase the resistor power (either increase the number of parallel resistors or increase the voltage across the resistors) so that the temperature again stabilizes after about 2 to 3 hours (or more) at 120 degrees F. Again calculate the total power used – light bulb and resistor power. How has it changed? Did you save any money by switching to CFLs?
The box at 120F is like a house in the winter where you have to heat the house to keep warm. The results of this experiment should be surprising in that it will show that there will probably be no savings at all from using CFLs. Worse – it can be shown that if the energy to heat the house comes from natural gas and the electricity comes from hydroelectricity (or nuclear) the CFLs will actually hurt the environment by shifting energy usage to fossil fuels…
- JohnsHopkinsLv 61 decade ago
Sprinkle some powdered coffee creamer onto an open flame. It starts on fire. And it's much better than ingesting that stuff.
- Anonymous1 decade ago
If a modest population would prevent global warming