Building Definition and 919 Threads

I have a minor bit of circuit experience. As a fun project id like to build a shortwave radio. Does anybody have any tips on where to start.

http://www.bloomberg.com/apps/news?pid=20601080&sid=aF3XI.TvlsJk http://www.scientificamerican.com/blog/60-second-science/post.cfm?id=why-not-spend-21-billion-on-solar-p-2009-09-02 Well this should be interesting. Japan is one of the leading nations in nuclear power and is not afraid to make...

Homework Statement perform a calculation for an object moving vertically in air under gravity and experiencing a retarding force proportional to the square of the objects speed. see (W=.5(cwpAv2) Object is dropped off a 100 meter building from rest. radius of object = .0366m mass = .145...

I'm making a small-scale aquaponics system at home (except I'm not eating the fish). There might be some random chemicals that will probably leech into the water from the materials I used (plumbing parts degrading/oxidizing, etc.), or had directly added (I used household ammonia to begin the...

Homework Statement 56. Finding the Height of a Building To measure the height of a building, two sightings are taken a distance of 50 feet apart. if the first angle of elevation is 40 degrees and the seconds is 32 degrees, what is the height of the building? Homework Equations...

For the same building with square vs. circular concrete columns of equal number and cross-sectional area, under what environmental conditions would one be preferred over the other?

For a given spatial volume and amount of material, what practical structural design conserves temperature best?

Say you're building your own house and you want the wiring system to be truly upgradeable. You know you can't just put the 'latest and greatest' data/electrical jacks in it, because those too will become obsolete. I've been thinking that in my next dream home, I would want PVC pipes going...

I have been looking through the forum for help on working out what i would need to build an electromagnet to certain specifications, but as i have not done anymore than a grade nine level physics frankly I don't understand most of what's in the posts. So if you reply can you break the physics...

Ok so for those of you who have followed my recent threads, you will know that i am trying to find practical ways of obtaining a 16 kA DC pulse to create a magnetizing field. I have tried to locate a strong spot welder, but the DC pulse is three phase and results in a non uniform magnetic field...

I know that answers to the following can sometimes be subjective and biased... but still... What are the most 'promising' models in string theory, judged by the potential realization of a realistic SS standard model? Also, in particular, how do Intersecting Brane Models (since their...

What have you built from junk/ stuff laying about your garage or whatever. My next project is to build one of them ( ionic wind) lifters from bits i can find or salvage.

I'm trying to build a C or H-frame electromagnet that produces a flux of 1.4T in the gap between its two poles. (See: http://cyclotron.lbl.gov/images/Cyclotron%20yoke.JPG ) But I can't find any references on building C/H-frame electromagnets. I calculated with permittivity of free space...

Hii Iam new in this field, Please I want to build 1/4 wave cables and cross diodes together to stop high power at 90 MHz frequency for exaample, I want help how can I build some thing like this and what is the equations to choose the right length depending on the frequency...

I'm not kidding. Two black vehicles, serious looking, and men in black suits are right outside. Should I post a pic or will that piss them off? Something's up. There aren't too many people in my apartment building, so they're probably here for me. Maybe. I've got to come up with something...

Building Materials Refractive Index?? Hi all, does anybody know the refractive indices of these materials (used in houses)? - Wall bricks - Wood (used in doors) - Glass - Plastic - Concrete (in ceiling and floor) and any other common materials :) thanks in advance

Hi everyone I work for a very small company, which produces steel products. Predominately from one particular hot rolled steel profile. (1040 grade) We currently subcontract our hot rolling to small chinese operators :( I know... At this stage our volumes are not large enough to warrant...

Im new to this forum and wanted to see what you think about my new patent pending design. My concept is...using a 2.5Mw wind turbine, refit 110'L rotor blades with a 10-12' diameter of concave vanes or paddles designed to capture max air thru a forced ducted system that is generated from a large...

Hello everyone, I hope I came to the right place for this type of question. Please assume that I am completely ignorant with regards to circuits/electronics (although if you can go into further detail, that would be very helpful in the long run). I am looking to build a simple miniaturized...

Hello I'm a visual artist and I'm trying to make a project were I need to add a sound to a photograph hang to a wall in a picture frame.The source of the sound it will be a ipod (unless someone has a better idea)I need to build a device to make the music from the ipod place in the narrow place...

which best program for building forums and web page

I hope I am posting this on the right section... In my Environmental Science Class, we are to design and build a solar oven(without using solar panels!). We will be baking a cookie. Me, being a "mathematician", remembered something about a parabola, that if light ray hits anywhere on...

ive done a search on google and found a lot of things about supplements and muscle building etc. im wondering what factors affect the amount of testosterone in your body? ive read working large groups of muscles increases it, and also exposure to sunlight (apparently) can anyone...

Hi, I am supposed to build a controller for a 5 wire servo. I'm having trouble finding information online that appeals to electrical engineering folks. What are the 5 wires? I suspect there is power and ground, but that leaves 3 unknown connections :eek: I have a basic understanding...

This is not homework, I'm just curious. Perhaps it belongs in the Engineering Forum, but the last one of these I posted there just got left in the dust. I have a rather specific question to ask those of you who are familiar with paper airplane building/structure/dynamics. How would I go about...

Currently I am doing a straw building project with a group and we are in need of an interview from a real life engineer. So if anyone can help me with my design on our Girder Bridge then it would be appreciated.

Homework Statement Spider-Man steps from the top of a tall building. He falls freely from rest to the ground a distance of h. He falls a distance of h/4 in the last 1 second of his fall. What is h? Homework Equations All kinematic equations with free fall. The Attempt at a Solution...

Homework Statement A projectile is fired from the edige of a building with initial velocity of v0=10 m/s at an angle of 45 degrees. The rojectile rises and then lands oln ground at point P as shown, which is 35.4 meters away from the base of building. A) Find the Y component of the projectile's...

all I really need right now is a 5 pound small weight that can fit in a spoon but I don't think there is anything that size that can fit in a spoon that would be lying around a house so what is a good projectile for the trebuchet the size of this one which will have a base of 75cm^2 or about 38...

Homework Statement I'm studying logic gates and trying to create my first one. Homework Equations 3. In a TV programme, the panel votes on new performers. The panel consists of a Chairman (C) and three others (X, Y and Z) who each press a button to register their vote. The SUCCESS light is...

As a summer project I was thinking of building an entirely mechanical Turing machine - possibly with Lego. Has anyone attempted this? Does anyone have any advice on how to design this? Thanks.

Hi everyone, Can anyone tell me how to build simple solar energy generator for kid of age 5 – 7 year? Please tell and send me with some drawing. Thank you very much in advance Huygen

First post here, although I could eyeball this project I have been stumped as to how it would be calculated. I haven't been in a geometry class for nearly a decade so this really brought to light how much I have forgot. I need to find how tall a board would be cut if it descends at a certain...

i need help minimizing the cost of this building? immediate help pleasez A university has decided to build a new, creative dorm! After a contest to determine the shape, it was decided that the dorm would be in the shape of an airplane hangar that has semicircular ends. There is an additional...

Hello all! I am building an effects pedal for my guitar (dont have a choice, I spent all the money I was saving on the guitar). Since electronic components are cheap, for once, I am glad I am studying EE. At first I thought I'd design the circuits myself, but after doing a bit of research, I...

i want to build a matrix that can solve cross product multiplication of 2 vectors, building a matrix A so that detA=PxS A= \hat{i} \hat{j} \hat{k} P1 P2 P3 S1 S2 S3 how do i build a code so that my det will give me a vector answer?

Is it in any way possible to build a 10 watt (battery powered) handheld laser?

I have limited hardware components I can use for this obstacle. Let's say I have precision rectified the input heartbeat signal into a square wave... I am trying to count the number of squarewaves/heartbeats and display them on two 7-segment displays refreshing every 15 seconds... I can only...

Homework Statement I'm building a hovercraft, and I'm familiar with how to calculate center of mass--however, there's something that will be sitting on the surface of the hovercraft that's throwing me off. I just can't seem to get it to work. I'm just trying to find what the mass would be at...

Hi everyone, I'm new to this forum. I'm working on a senior project where we are using ultrasonic transducers at very high frequencies. Problem is we only have some weaker 25V power supplies to drive the transducers. To fix this problem we were going to purchase a power amplifier but due to...

1. How to attach my wheel, plastic lids with rubber bands around, and axle, a wooden dowel rod 5/8 in diameter, to the car body, which is a board of wood? I used a wood block and attached the too the body and drilled a hole big enough to slide the axle. I also put a piece of aluminum around...

the instructions for building it is that we can't use anything for the car that would be used in its original purpose so like for wheels we couldn't use actual wheels. I want to make it pretty big but light at the same time and the goal is to have a car with fast acceleration and that can go...

also, i am unsure about the units...are the above ones ok? as in the website had these units [ KWh/m^2/ hello everyone! i know that solar collectors are commonplace in many parts of the world (tho not mine) so this might sound a bit stupid... anyway, i wanted to make (actually build) a solar...

We are trying to build a bridge made from paper, water based glue and cotton strings. The bridge must be able to hold 5kg; however, we would like it to hold more weight. The weight of the bridge should also be taken into consideration. So we came up with numerous designs and we finally...

I'm fairly experienced with computer hardware and software, but I've been out of the game for awhile in terms of buying new machines. I'm looking to buy/build a computer for academic work (computational astrophysics). I have about $2000 to spend, and I really want to maximize the power that this...

I'm trying to build a betatron with the electron gun from a television. What do you think would be the best material for the tube of the electron gun? Also, do the electrons need to be accelerated further after being emitted from the electron gun, or do I just need to guide it with coils...

Homework Statement Need to heat 30mL of water from 20C to 40C in 1 min(60s). Using 6V battery and Nickel Chromium alloy Nichrome wire that has a resistivityabout 10^-6 ohms/meter. So you use the battery and the wire to build a water heater. Batter has no internal resistance. Homework...

I'm not understanding something very basic here. I know what voltage drop is. At least I thought I did. Here is a question: Assume you have a power supply in a control panel of a building. 500 feet away is the load device. When doing voltage drop calculations for the wire (500 feet...

About thirty years ago I was experimenting with some electrical/magnetic devices and found that a machine called a Kirlian machine would light up the path (coronal discharge) of magnetic fields and so I could visually see the presence of a magnet field and therefore an electrical current as it...

I also have a membership at scienceforums.net and posted this to try to figure out what went wrong, but my post has been up for a week with 100 views and 2 replys both saying that they have no idea what I'm talking about. Hopefully I will have better luck here. Quick introduction: I am 16...