Engineering

Since we light buildings with 60 cycle flourescent lights, we are actually being strobed 60 times a second and in the dark 60 times a second. I have a doorway 8ft high by 3ft wide and I rig it so a 2" metal bar drops from ceiling to floor spanning the doorway on a chain drive in the walls. Then the bar returns up behind as another drops in front connected to the same chain. With 24ft of chain in the loop and about a 1000 rpm motor and gearing I could have the bars drop from ceiling to floor in less than 120th of a second. I could time it so the bar only dropped in between strobes. Wouldn't an observer see an empty doorway but experience an invisible wall of steel? …

I watched 60 Minutes on Sunday and they showed a factory building 2000lb dumb bombs. What I was curious about was why did they fill them with concrete? I saw them pour concrete in the 9 foot hollow shells stood up on end. What is the physics or common sense logic behind this? Why not BBs or scrap metal? Just aman

I figured this was more appropriate than the Computer science forum, since this is more of an electronics question. I've noticed that many computer power supplies have a label on them, listing things like "+12V, 15A" and "-12V, 0.3A" and suchlike. I know the V and A mean volts and amps, but I'm a bit unclear of the meaning of the + and - signs with respect to voltages. Isn't voltage always a difference in potential, thus doesn't get a sign like that? Basically, I want to hook something up to the power supply with a 2 Ohm resistance, and I want to know what wires to connect it to. Mokele, probably well out of his depth on this project.

If you sow the movie with the super gun for Iraq you will know what I suggest : Big gun that will fire small craft’s in the orbit in the shell , at some altitude shell will break and craft will start his own engines What are you think it will cost more or less for launch of the craft Jules Vern

hi, iam having my 7th semester of b-tech in ECE. this 29 infosys is coming for recruitment. so pls sent me with good tips and some important qns pls... also sent me any materials for wireless commn and cryptography .. pls ........................pls................ -----Venki

I found a "Dynex RF Modulator AV Signal Converter WS-007" in my house. It's about 2 years old and since it's no longer under warranty support won't offer any help. When I plug it in the red light on the front lights up for a split second then fades out jut as quick. It doesn't matter whether my rca cables are plugged in or not. When the red light comes on, the video signal from my camera shows up on the TV, but then disappears as soon the light fades away. I was thinking of opening it up, but I'm not sure what to look for. Any ideas?

If you've ever seen the movie "the hunt for red october" (tom clancy novel), it says how a submarine has a silent propulsion system. they explain it as a jet engine for water, but with no moving parts. i was just curious if this is even possible, and if it is, how it would work. I've been looking at the site, and i like it, im only a jr. in high school, so i don't understand too much of the real technical stuff yet. but i think im leaning toward engineering for a career and all. another quick question, how do nuclear reactors transmit energy from nuclear to mechanical? is it steam...can't remember for some reason right now. wonder if zarkov has any cr…

is there anyway to make a bomb that wen explodes it freezes everything in the blast radius?

i was surfing the net yesterday and found somthing about these engines that they use less fuel and give out more power i wanted to look at a diagram of the PDE but never found one and would like to find out more about ho these work since i am unfamiliar with them

I just thaught about a camera which is spherical and can catch up all things in its sorrounding, lly as we take a look standing a place. Then this camera sends information to a device i call it Arti-enviro. It means artifecial environment which is also a spherical LCD display, viewable from its inner surface (we have to enter a spherical room) This room shows us the same environment as catch up by the camera. The query is that is such type of thing alreadily done, on search, or impossible........What do U think

Is it at all likely that we'll eventually be able to build things on scales smaller than nanoscale? What problems would we encounter when building things out of nucleons, or even quarks? If the quark has a substructure, could we go beyond? Is it at all feasible that we'd eventually be able to build even on the planck scale?

I don't know if at one time NASA studied the feasibility of growing plants in space for oxygen and food, and I don't know if this idea has been overlooked or not: It is much less feasible to use any kind of fluorescent or halogen lamps in space, because of weight, power requirements, fragility, poor lifespan, and bulk. LEDs are becoming just about as power efficient, and they generate little heat, are much less bulky for the light they produce, weigh a lot less, and are very much simpler to install. They can be handwired if they have leads, soldered to circuit board material in easy to build arrays, are extremely sturdy compared to light bulbs and fluorescent tubes,…

http://en.wikipedia.org/wiki/Nuclear_thermal_rocket any thoughts?

What is up? Me and a friend of mine are going to be attempting to turn his car into a hydrogen fueled car. The way we see it, it would actually help the ecosystem because it would be releasing much needed oxygen into the atmosphere instead of CO2 (I think?). If we succeed we will be entering it in for scholarships and the like. We are both going into a field of some kind of Physics. I know he wants Theoretical, I dunno what I am doing though. Anyway, does anyone have any suggestions on some ways to do this? Has anyone had any experience in trying to make one and have any tips? Thanks for any help. EDIT: First, we will be working with lawn …

anyone could tell me how it is and how it work (a transiente noise simulator)? (no too much specific) what is a incidence matrix in a network? (i only need to know the "technical" definitions)

Heres a problem I've tried doing for ages but I can't quite get it right The answer is *apparently* approximately 10.8 degrees. Heres the question and a diagram to help visualise: Three smooth cylinders are stacked up in a trough as shown in the diagram below. Each cylinder weighs 400N and has a diameter of 125mm. Calculate the minimum angle theta which will support these cylinders in equilibrium.

This on the picture will be the electro magnetic tunnel( like the trains are moving on the electro magnetic energy) the idea is to put rocket inside and speed up in the circle until reach good speed , and then release the rocket try the vertical tunnel . Rocket can also carry own fuel for additional speed The tunnel will be in vacuum What do you think - It’s possible to use on earth , inside the orbit , on the moon ( It’s so easy to produce electric energy out in the space , it’s hard to find material for fuel like H2 ; O2

How good is ceramic engine? and is there anyone actually using it in real life?

In case you havn't heard, RFID tags (like the anti-theft devices that are in most CD/DVD cases) have been getting a fair amount of press lately, and many people are concerned about privacy, namely that RFID tags in products could be used to trace what sort of things a person buys, or can be used to trace the person themselves etc etc. Basically I am wondering how one would block and RFID chip. I was thinking that just having a faraday cage around it would block it, as that would at least block the radio waves. However I only have a vague idea of how RFID chips work, and some might use magnetic fields instead of radio waves (I have no idea). So would a faraday cage do …

I'm currently harvesting a large amount of capacitors off of an old vcr. I don't know exactly what I'll use them for, but I will need to know how to charge them. So, long story short, what is needed for a capacitor charging circuit?

I'm doing a 4 year course in engineering. Not sure what I want to major in, but the degree is electrical engineering. I was considering electronics, because an interest I have is security system design. But control systems engineering looks interesting. But is it just me, or is the course incredibly hard ? First semester in first year was good, ever since then my grades have been dropping. I am not sure why, I put in the effort, but it doesn't pay off. I am taking a classical control subject, and a stochastics subject. Both are going to be a struggle.

I've just been accepted into a Masters coure in chemical engineering at Strathclyde University in Scotland. Anybody else here studying or studied this? If so what am i in for?

This is an engineering problem. The idea, and I think we are up for it, is to engineer a device that can render the supervolcano under Yellowstone park inert, or at least a lot safer than it is right now. Hopefully time is on our side, but we don't know more than we do know about when it will go off, covering most of North America in ash. We even have the potential ability to cover the area with cubic miles of rock and dirt. It's not impossible, it's just difficult. We could try to do a controlled release of pressure through pipes. Again, not impossible, just difficult. If we could harvest the volcanic ash produced by controlled release, the project might pay fo…

Hi, im looking at Pressure sensors, to measure the pressure experienced at the end of a line in water. However, they are all rated in PSIA or PSIG And im confused I just need PSI Any help clearing this up would be greatly appreciated

Can a diesel engine run on water due to its low combustion ratio? Also, I was watching a Steven Segal film in which he was helping a native American girl to save the world from pollution and self destruction. I cannot remember the title however it had John C McGinley in it. Anyway, the point is at the end he made a speech about how there was already a combustion engine available that can run on water. Is this true? Thanks for your help lads and ladettes Bob