Get hold of a high definition video, and high speed with frame rates 240fps, 480fps and 1000fps (although 480 fps and 1000fps gives a small image and needs really good lighting). Several experienced physics teachers agreed with a colleague's comment "I haven't found anything yet that we can't do with 300 fps". Alan Whyborn said "Last year I tried to do an analysis of a car traversing speed bumps at different speeds - found that 120 or 240 was best to analyse in detail the difference in motion between wheels and cab (240 was almost TOO fast). Water rockets at 320 would be excellent to evaluate the thrust phase. I would be happy to go for that. Would like to see how it handles an arrow though". The Casio EXILIM ZR100 High Speed Digital Camera (about $300) is fantastic according to physics teachers who have used them for motion capture. For example, see the Water Rocket EEI above.
(Some ideas: football, springboard diver motion: s/v vs t; what variables to change; must collect first hand data).
You may have tried an experiment where you magnetised a nail by rubbing it with a magnet and then when the nail was heated it lost its magnetism. Magnetic Field Strength is affected by temperature. This makes an ideal EEI. In his Year 12 EEI at Villanova College, Coorparoo, Brisbane, student Peter Bergin wrote:
"When the magnet is cooled, the borders of the domains slightly move so that the alignment of the domains are further preferential and create a stronger magnet. If the temperature of a magnet is raised, it causes the random thermal motion of the atoms to increase. This motion randomises the domains and the borders are shifted so that they are no longer in a complete single direction like the domains were previous to heating".
He used a Hall Effect field strength probe as shown in the photo below. Peter found a field strength of 45.2 mT at -25°C down to 43.8 mT at 20°C. He suggested liquid nitrogen would be interesting. The EEI may be strengthened by a more direct measurement of the field strength. Rather than a "black box" probe, you could estimate the field by measuring the torque on a compass needle or by the rate of oscillation of another magnet swinging in the field nearby (as they did in the olden days). A comparison of different types of magnets, or length of heating time or different ways of measuring B would be worthwhile.
Be warned about information you get off the internet about thermocouples. One popular site says a thermocouple is "...a junction of dissimilar metals that creates a voltage you can relate to temperature." This misinformation continues to appear on company web sites, in application notes, and in articles. You could make a simple thermocouple from copper and iron wire (see diagram below) using boiling water and icy water to calibrate your device. Then you could investigate the cooling curve (and time constant) when the hot end is allowed to cool in a gentle breeze. Or you could look at ways of forming the junction (twisting, soldering, welding). Or how about different alloys and what factors influence the voltage (resistivity perhaps). There are lots of things that would make a great EEI.
Please note: it is all very well to make spectacular and intricate trebuchets (eg carved and polished oak or pouring your own lead counterweight complete with ancient inscriptions of battles won), and it is all very well to do heaps of testing (battling each others castles on the footy oval); but unless you meet the requirements of the criteria in analysis, discussion, evaluation etc there is little hope for a good EEI grade. Be warned! Your teacher will also be concerned about safety (see "" note above). You will have to get parental supervision if you are using power tools or testing it at home. Secondly your teacher will no doubt place a limit on the size of the throwing arm/counterweight or the projectile. Some teachers have wisely said: the trebuchet must be small enough to fit on a school desk; the projectile should be soft, eg a softball; or the projectile should have a mass no more than a golf ball. Teachers report some lethal trebuchets used to launched huge projectiles in the back yards of suburbia. However, there have been students who made ballista (ie catapults) out of paddle-pop sticks and received an "A".
Another way to think about my technique is that it gradually increases the average density of the fluid in the well hole until that column of fluid is so heavy that the high pressure at the bottom of the hole is unable to lift it. The liquid starts out as a light mixture of oil and gas, but it gradually transforms into a dense mixture of oil, gas, and iron. Viscous forces and drag forces effectively couple the materials phases together to form a single fluid. Once that fluid is about 50% iron by volume, its average density will be so high (4 times the density of water) that it will stop flowing upward. If iron isn't dense enough (7.8 times water), you could use silver cannonballs (10.5 times water). Then you could say that "silver bullets" stopped the leak! The failed "top kill" concept also intended to fill the well hole with a dense fluid: heavy mud. But it required pushing the oil and gas down the well hole to make room for the mud. That displacement process proved to be impossible because it required unobtainable pressures and pumping power. My approach takes no pressurization or pumping at all because it doesn't actively displace the oil and gas.
In modern fluorescent lamps with heated electrodes, however, the role of the ballast has been usurped by a more sophisticated electronic power conditioning device. That device converts 60-cycle alternating current electric power into a series of electrical energy pulses, typically at about 40,000 pulses per second, and delivers them to the lamp. The lamp's flicker is almost undetectable because it is so fast and the limited energy in each pulse prevents the discharge from consuming too much power. It's a much better system. Compact fluorescent lamps use it exclusively.
Since the density of a liquid usually decreases with temperature, it is not surprising that the speed of light in a liquid will normally increase as the temperature increases. Thus, the index of refraction normally decreases as the temperature increases for a liquid. For many organic liquids the index of refraction decreases by approximately 0.0005 for every 1°C increase in temperature. However for water the variation is only about -0.0001/°C. A good EEI would be to examine the relationship between RI and temperature for water and perhaps other liquids. Does it vary regularly with temperature; is it related to the coefficient of volume expansion; do solutions of ionic or molecular solutes have any effect and, if so, why? The possibilities are endless. You need to get hold of a triangular tank which can be filled with the liquid and a laser beam shone through it. Lie it flat on a hotplate and away you go. You could easily make one from microscope slides and epoxy glue or silicone.
How to make this an EEI? You could consider making a series of measurements at different water depths and plotting them to see if RI is constant over the range of depths. The accuracy of the smaller depths can be commented upon. You could always perform this on a hotplate as in the above experiment and look at RI vs temperature, or you could think of something more imaginative. My thanks to Prof. Shyam Singh, Department of Physics, University of Namibia, Windhoek, Namibia for this suggestion (, March 2002, p152). Read about safety in suggestion above.
Refraction by ice is of huge importance to astronomers and environmental scientists. Water is a dominant building material for solid celestial bodies: it makes up the polar ice caps on Mars and is a major component of interstellar 'dust'. Astronomers use radiation in the Far Infra-red (Far IR) to penetrate this dust but they need to know a lot about how light refracts as it passes through. Here on Earth the optical properties of clouds are also critical: we know that Cirrus clouds are composed of water and ice and that they play and important part in regulating the Earth's climate variability. And what simpler way is there of measuring the thickness of Artic ice (even 2 km thick) than by sending radiation into the ice and measuring aspects of its refraction and reflection.
Instead of buying the Zero Toys you would be better making your own so that the variables can be manipulated more easily. There are plenty of instructions online to choose from; but a can (eg soup, canned fruit) with a balloon over the open end and a circular vent in the other is a good start. When you gently flick the balloon end of your vortex launcher, a transparent ring of spinning air will shoot out of the hole (you can feel it and blow out a candle metres away). You need to make the ring visible so a smoking incense stick may help (or make clouds from dry ice in water and inject into the can through a tube). How does the hole size affect the ring? How does greater stretching of the balloon affect the ring? Good EEI variables.
The discovery that the motion of a magnet past a coil of wire produces an electric current was made by Michael Faraday 160 years ago. Since then this relationship has been investigated by countless scientists, engineers and students. You would think that there is nothing left to discover but some interesting things are always thrown up by investigators. Electromagnetic induction makes a good EEI, partly because it can be done simply and partly because interesting data gives you lots to talk about. Physics teacher at Urangan State High School, Queensland, Australia, Alan Whyborn describes an experiment that could be the basis of an EEI.