| Author | Message | ||
     Ryan Somebody |
This isn't actually about a science fair, but more about the absence of a science fair. I really have no source for information (being in 8th grade); anyway, i have several questions: Lets start with this- Nickel is ferromagnetic, right? If so then wouldn't there be a attraction to the second (non-ground state) ball bearings to the first magnet? I know this probably very minute, but just wondering. Second- I also plan on building a "gauss rifle" in either a pvc or metal (aluminum or copper) pipe. Any tips on how to "reload" the gun? I just don't know how I could mount the magnets inside without glueing them- making reloading quite difficult. Perhaps I could drill a groove through the entire pipe... Yet more- ( I know this is long ) I don't quite understand that last bit of physics in the Gauss Rifle page... I understand the increase in speed is not linear- are you saying the acceleration rate is decreasing?? How much does this affect the velocity?? I assume the acceleration may decrease due to the increasing lack of space for the magnet to accelerate the ball bearings, so could I make the acceleration linear by increasing the space between each preceeding magnet? Last and least- what grade are those magnets your selling? I know they're strong but I have yet to use them. ND40? Also- would using more powerful, larger magnets increase the velocity of the projectile (substansially)? Any other sources for these solid-state linear magnetic accelerators? I keep finding solenoid/electromagnet sources (coilguns). Your the first site I've seen to feature that type of accelerator. I'd like to build a solenoid-driven coil gun but I get velocities of about nill on 28 volts (all I have is two drill batteries- no power source). Thank you for ANY answers and I am VERY pleased with your site. It has inspired me and (like you said) I can't wait to get out of school to work on these projects! Also, please keep the 50 ball bearing order option in your catalog- I noticed that it dissapeared and I almost had a heart attack. I have no clue how to find them in my area (NH). Thanks Again! P.S. - Can I link to your site? I'm trying to make a sci-fi science and computer site (yottabyte.150m.com) It'll be updated soon. | ||
| Simon Quellen Field (Sfield) |
The first ball sticks to the magnet. The second sticks to the first, but not as firmly. It can be knocked off easily by the momentum of the ball that strikes the magnet. I wouldn't bother with a pipe. Just use a groove in a block of wood, or a piece of U shaped extruded aluminum. The accelerator adds a fixed amount of energy in each stage. Thus it is linear in energy. However, since energy equals half the mass times the velocity squared, the velocity goes up with the square root of the energy. So it isn't anything you can fix, it is just the way the math works out. Our magnets are the strongest that can be made. They are 48 MegaGaussOersteds. The ND40 number you quote is some manufacturer's name for a 40 MGOe magnet. Other manufacturers use different terms, such as N40. Ours would be ND48 if your manufacturer could make them. The magnets must be close to the same mass as the balls to get effective momentum transfer. Think of a BB hitting a cannonball -- because of the mass difference, the BB bounces off, rather than moving the cannonball. There are many good web sites that cover coil guns. I don't know of anyone else who has come up with my design. Lastly, we love to have people link to the site. We even link back. | ||
| Ryan Somebody |
Thanks alot for the reply. I have a better understanding of the concept now. No wonder you bost about your magnets I didnt have any clue they were that high grade! I look forward to ordering them. | ||
| alasdair kempton Unregistered guest |
I am wondering about the possibility of using plasma as a projectile in a magnetic accelerator, this is all theroy, as i do not have the resorces to creat plasma nor do i want to explain why (if it worked) the entire row of houses where i live all have sizable smoking holes through them, or (if it didn't work) why i have very severe burns and/or have died. all i want to know is, is it possible in theroy or ist it just sci-fi? thanks, alsdair | ||
| Simon Quellen Field (sfield) New member Username: sfield Post Number: 206 Registered: 12-2004 |
It's easy to make plasma. You do that every time you turn on a fluorescent light. You may have noticed that the plasma in the light does not create smoking holes in the glass of the light bulb. Plasma has very low density, and is very easily cooled by contact with solid matter at room temperature. The plasma in a lightning bolt is not what is doing the damage -- the electrical current is what is heating things up. ` | ||
| alasdair Unregistered guest |
Ahhh... that explains it, confused fusion with plasma  . by the way, how do you creat a plasma? | ||
| alasdair Unregistered guest |
bad post, srry, wrong question. don't worry about my last post. | ||
| dustinl (Unregistered Guest) Unregistered guest Posted From: 63.84.103.226 |
Created a magnetic accelerator for science fair. Moved magnets at intervals of 6,8,10, and 12 inches and tested velocity between each magnet. Interestingly, the velocity was highest with the magnets at 6 inches apart and at 12 inches apart. The balls had least velocity at 8 inches and then at 10 inch.What I understood is the closer the magnets,the increase in velocity. Can anyone explain? | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 993 Registered: 12-2004 |
Show all of your data, and we can see if it fits a curve. If the data has a large random component, then experimental error may be coming into play. Running the experiment many times can help average out the error. | ||
| dustinl (Unregistered Guest) Unregistered guest Posted From: 63.84.103.226 |
I have tested many times, still I cant figure it out. Here is the file... popattach{1629,magnetic accelerator data} see if you can figure it out... Thank you for your help. | ||
| Umei (Unregistered Guest) Unregistered guest Posted From: 64.231.48.193 |
hi, i was wondering that doesn't this defy the law of momentum and law of kinetic energy because if u were to calculate the momentum and the kinetic energy of the ball before the collisoin and after the collision, it will clearly be different? and also can u guide me to do this in a way so that i m able to get some values for the velocity, force etc. and then try to see the relationship between the magnets and the velocity of the last ball? Thank you for any answers. | ||
| Simon Quellen Field (Sfield) Senior Member Username: Sfield Post Number: 1594 Registered: 12-2004 |
The toy breaks no laws of physics. Show us your calculations and your reasoning, and me might be able to help. | ||
| sondrahilton (Unregistered Guest) Unregistered guest Posted From: 98.17.71.13 |
My son has a science fair project to do and has chosen the magnetic linear accelerator. He is in 7th grade and much of the concepts behind this gun are way over his head. Can you suggest a simple hypothesis for him to prove preferably involving distance since that would be the easiest to actually measure (versus velocity, energy, rate,...). He must also write a research paper on it and much of the information is on rail guns and coil guns. Can you suggest applications for this simple magnetic linear accelerator or similar applications. To keep it simple, would a paper discusing definitions of energy, (both potential and kinetic), conservation of energy, transfer of energy, and acceleration cover most of the dynamics occuring here. If not, can you break the process down in a way that he can discuss and tie in each component. As you can tell, I am not a physicist. Would appreciate any help. Keep it simple but enough to have a 500-700 paper. | ||
| Kasper Emil Feld (Magnetfeld) Intermediate Member Username: Magnetfeld Post Number: 31 Registered: 11-2007 |
"To keep it simple, would a paper discusing definitions of energy, (both potential and kinetic), conservation of energy, transfer of energy, and acceleration cover most of the dynamics occuring here." Yes | ||
| need help (Unregistered Guest) Unregistered guest Posted From: 121.210.121.18 |
I would really like to create a magnetic linear accelerator for a science fair but i need something to test(hypothesis). Would you be able to make any suggestions. | ||
| diana (Unregistered Guest) Unregistered guest Posted From: 67.213.248.61 |
i have a couple questions... my son is doing his sciencefair project on the gauss rifle. could you please help us with hypothesis and also could you tell us where we might be able to buy the magnets and the steel balls for the project | ||
| Theresa Simmons (Theresa) Senior Member Username: Theresa Post Number: 134 Registered: 1-2008 |
Get the magnets and balls here: "http://www.scitoyscatalog.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=GAUSSRIFLE&Category_Code=M" Does the spacing between the magnets matter? Should the magnets be spaced farther apart in later stages so the time it takes the ball to get between magnets is a constant? If a piece of glass (like a microscope slide) is put between the balls, does that make the final ball go faster? Does it work better pointing North? Does it work better with four magnets than with three? | ||
| JimS (Jimmy101) Member Username: Jimmy101 Post Number: 15 Registered: 2-2007 |
http://scitoys.com/cgi-bin/board/show.cgi?tpc=1&post=22972#POST22972 i have a couple questions... my son is doing his sciencefair project on the gauss rifle. could you please help us with hypothesis and also could you tell us where we might be able to buy the magnets and the steel balls for the project Adding to Theresa's suggestions; * does more than one magnet per stage work better? * what happens if there are three (or more) ball bearings in a stage? * is the increase in the ball velocity the same for each stage? * is the increase in the ball energy the same for each stage? * what if the ball bearing nearest the magnet isn't iron or steel? (perhaps try a glass marble?) * what kinds of iron and steel work best for the two ball bearings? (Check www.McMaster.com for a variety of chromed iron and stainless steel ball bearings. There are many type of stainless steel and the various types will behave very differently in a Gauss rifle. Some types of stainless steel won't really work at all. Chromed iron is often the best ammo.) To change any of these (or Theresa's) suggestions into a hypothesis suitable for a Science Fair project you just have to make a prediction of the answer to the question. "A Gauss Rifle with three chrome steel balls per stage will outperform a two ball per stage version." You might want to take a look at http://www.inpharmix.com/jps/Gauss_rifle.html. It describes a fairly simple way to measure the rifle's performance. For a decent science fair project you must be measuring something, you must do at least a few replicates and you must do at least a simple statistical analysis. For grade school and middle school the average of several shots would be the minimum analysis. The standard deviation would also be good. For a high school level project the statistical significance of changing various parameters of the gun should also be included. (Message edited by jimmy101 on November 6, 2009) |
