Building Definition and 891 Threads

Hey guys, I need to build a simple device that climbs a length of string (about 2 metres) without any support from above, and with energy from only the descend of a 200g mass. Speed is of importance. I have considered using two pieces of gears secured onto the string with rubber bands...

Homework Statement Design a solar cell, designed to absorb solar light. Treat the sun as a blockbody source of T=5800K. To design the cell, you may grow 4 very thin semiconductors of the following bandgaps, in eV: 1.43, 1.14, 1.35, 0.67, 1.75, 2.4, 2.7, 0.42, 3.37 Which of these would you...

I have been taking some foil and various "dielectrics" in attempt to build a capacitor. The best I have done so far is an extremely low capacitance (potential difference drops fast even on reading voltage with great resistance) where I will get about 3v for a few milliseconds after having...

Hello, I am in Grade 12 physics class and I have been given a open ended project; where we are required to build/create a machine which would involve at least 6 of the physics concepts: ramps, pulleys, levers, transfer of momentum/energy, projectile motion, circular motion, stored elastic...

new to this project and have limited knowledge, but the failure is consistent thru all specimens so I am hoping someone could shed some light. Film cap design is rated to 1650v Failure- Cap initially failed around 800v consistently, the curing time was adjusted and a ramping cycle was...

I am planning to build the amplification circuit to amplify the signal from my signal generator by myself. Can someone tell me the what type of materials are necessary for me to get started? What kind of book will be helpful?

Hello, I'm looking for some feedback on and an analysis of a spreadsheet calculator I've made. It looks at temperature changes over time, given starting volumes of a building shell and thermal mass. The calc takes into account building fabric and ventilation heat losses. First I've...

Hello, I am a civil engineering student and I am currently taking a project design class that requires a bit of overlap into the mechanical field of thought. We have designed a 3-story108,339 sf. building that needs energy-efficient HVAC&R systems, among other things. Being a civil engineer, I...

I've been watching Sidney Coleman's QFT lectures (http://www.physics.harvard.edu/about/Phys253.html, with notes at http://arxiv.org/pdf/1110.5013.pdf), and I'm now on to the spin 1/2 part of the course. We've gone through all the mechanics of constructing irreducible representations D^{(s1,s2)}...

As part of an assignment, I have been asked to construct a tower that is completely made of paper and sticky tape. This tower must be built with 4 specifications: 1. Must be built of nothing but paper and tape no cutting devices, glue, ect ect. 2. Must be built within 5 minutes. 3. Must be...

I am helping my son design and build a refractor telescope for a science fair project (8th grade). He has read some on lens types and focal lengths. We also read that Galileo's most powerful telescope was 33x, and was able to view Saturn's rings and Jupiter's planets. We want to be able to do...

Want to know the posibilities of lifting over 300Kgs How much current will be required of electromagnets holding the coaster carriage lifted above two beams on either side? Also will it work to place electromagnets on opposing sides (top and bottom, left and right) of the beam to hold the...

I need help on how to cascade two or three Jfet transistor and the calculation of the values to have a good amount of gain. The cascade also should help in providing good linearity, have less distortion and should stable good stability.Thanks, good help will really be appreciated by me.

Hi, I'm a computer scientist w/ very little hardware experience. I've been playing with the idea of using NIRS for a brain computer interface. The basic principle is pretty simple: You have a laser diode and a detector that is 2-3 cm away from the diode. Unfortunately I have almost no...

I don't happen to have any welding equipment available to me, so I have decided to make an oxyhydrogen welding torch. That basically involves splitting water by electrolysis, running it through a tube with a blowback arrestor and burning it on the other end. I have read that the voltage should...

Hi, all! Unfortunately I'm not much of a computer guy, so I'm sorry if I leave out anything important. I'm attempting to build Cuba-2.1. The distribution I'm using is: [FONT="Courier New"]DISTRIB_ID=Ubuntu DISTRIB_RELEASE=10.04 DISTRIB_CODENAME=lucid DISTRIB_DESCRIPTION="Ubuntu...

I am interested in replicating Bob Beck's work in the attached PDF document, dating back to 1978. After building a variety of coils Beck was able to demonstrate EEG entrainment with a 9-foot coil and by broadcasting an amplified Schumann Resonance frequency. The idea would be to interface said...

I am building a moving target system for a shooting range. It will have a 40 foot target moving perpendicular to the shooter. I have not had any problem with fabricating the target system, but I want to go above what the customer requires. Hopefully this lead to more work for myself in the...

http://img816.imageshack.us/img816/1640/givenlg.jpg I think I might have exaggerated...

I am designing a game where you would shoot an IR gun at an object that would turn a light on and stay on until manually reset. I don't know much about electronics and any help would be appreciated.

Homework Statement Thank you first off for your help. Currently, I am working on a lab for my University Physics class and I am lost on how to do this integration. We weight (from a scale) and time measurements going up and down in an elevator. Using that data we are supposed to get the...

Assume that there is a original wall which does not have any defect inside. After an excitation of heat at one side of the wall, Ti is 37°C and To is 30° C. Thermal capacitance is assume 1. So the heat transfer is 7. For another condition, i want to find out if the wall has air pocket inside...

can all the parts be bought in hardwares? and if anyone has done this can you please give me all the parts needed, also the software you need to install using windows or linux

Is LISA the only option in detecting gravitational waves? Anyone have some insider info on the talks about cancelling, going with smaller scales, or just a general update on the situation? What else could LISA do other than observe that gravity waves are actually present? and what would it...

I recently began making a cabinet into a grow station. It's almost finished, but I'm having trouble with the lighting system. In the beginning the idea was to make a full-spectrum LED light array of no particular voltage. I wanted to mimic this array I saw on LED Lights and Light Fixtures...

I'm uneducated in Physics so I'm not sure where to begin with this. I want to build a vacuum chamber that is rectangular and fairly flat. It will measure 48"X96"X8" I plan on constructing it from clear polycarbonate sheet on one face (would clear acrylic be a better choice?) and aluminum sheet...

I've always found electrical engineering interesting and I am considering pursuing in a career in this in the future. I'm a junior in high school and I want to be positive that this is what I want to study for in college. So I want to start learning more about this and playing around with this...

So occasionally I see something in the news about some teenage who built a nuclear reactor in his basement. And just the other day, my girlfriend told me that one of her clients mentioned that her boyfriend is a Physics major at my university, and has a nuclear reactor in his garage that he...

Some of you may have heard about the "world famous Redneck Shop" in Laurens SC that sells Confederate memorabilia, KKK robes, etc. A black church now holds title to the building, but under the terms of the deed, they can't kick the Redneck Shop out until its owner dies! Uneasy Neighbors in a...

Homework Statement We must build a self contained device which can pass through a standard doorway. It will start .5 metres from the egg cup with an egg in it this egg cup is then .5 metres from a cart that the egg has to pass through and continue going to a target on the other side of the...

String field from Loop SpinfoamQG:how to build SM matter on discrete quantum geometry note: EPRL is the current standard spinfoam formulation of Loop Quantum Gravity. http://arxiv.org/abs/1201.0525 String Field Theory from Quantum Gravity Louis Crane (Submitted on 2 Jan 2012) Recent work...

How would I go about building a wave transmitter? Like in the noise cancelling headphones. I want to build a transmitter that absorbs sound waves, reflects them, and then shoots them out creating destructive interference.

Basically like a cellphone. I am aware that it is pointless, like most things in this life, but it makes sense if you want to learn about things. So I have a question Using knowledge on communication technology, and a bunch of old cellular phones, is it possible to combine all of that hardware...

I'm having problems trying to figure out how CO2 canisters work. I've never actually used them before so how would you connect a CO2 canister to a piece of piping. What I have trouble understanding is how you would open the CO2 cartridge and connect it to the pipe. Would it be by puncturing the...

Alright, so I was wondering if anyone could help me figure out from one step to the next... So we have defined |qt>=exp(iHt/\hbar)|q> and we divide some interval up into pieces of duration τ Then we consider <q_{j+1}t_{j+1}|q_{j}t_{j}> =<q_{j+1}|e-iHτ/\hbar|q_{j}>...

I am trying to upgrade my antique car while still keeping the factory look The rear defroster is a blower motor that sucks in cabin air and blows it onto the back window. The air in the cabin has to get warm before the windows will defog. I am thinking of helping that a little by...

Homework Statement Build an elastic-powered or gravitational-powered car that traverses on sand for 2 meters, then fires a projectile perpendicular to the car into a target 2 meters away. The car + projectile is marked based on: Distance traveled before firing (as close as possible to 2...

Hello all, I have been building a simple amplifier circuit(diagram attached) that will take in a source voltage and use a resistor divider to divide the voltage down on three different ratios, determined by a manual switch- 1/1, 1/4, and 1/40. It goes through a unity gain configuration...

hello everyone i have to design a simple two floor office building with roof. i am very lost and confused and don't know where to start from. can someone help?pleaseeee

I need to build a circuit to do the following: I am making some wine at home and need to monitor the process. During the fermentation process CO2 is produced so I need to monitor the pressure in the system and provide for a pressure release (back to 1.1 atm.) if the pressure gets too high (>...

Homework Statement m= 1.45X10^6 kg w=1.00X10^2 MJ a=0 m/s^2 to over come the force resistance that was 2.00 percent of the building's weight Homework Equations Fa=Ff (force applied=force friction) The Attempt at a Solution Fa= Fn-Ff Im confused on how to find the force...

I'm building an AC to DC power supply for a class and my question mainly revolves around the input and output of the whole thing. My source of confusion is where to include my DC output in a circuit such as I would assume that it would be the leftmost node of that full bridge rectifier...

What are these? http://www.wired.com/dangerroom/2011/11/china-gigantic/?mbid=ob_ppc_dangerroom This must be a driving training ground. What's strange is the way the lines are cut. Some of the curves are highly acute, yet the points are carefully constructed, not all the way a bulldozer...

I'm getting ready for my Christmas break project and I've settled on building a Tesla coil. I was looking at this << link deleted by Moderators >> but I'm still not really certain about what the components do and why they're needed. I kind of understand what a capacitor and transformer is but...

Homework Statement Supposedly, I put an object on a scale inside the elevator of a building, the scale reads m1. I start the elevator to the top of the building, during acceleration, the scale reads m2. As the elevator normalized, the scale reads m1. During the deceleration at the top, the...

Homework Statement A great conical mound of height h is built by the slaves of an oriental moarch, to commemorate a victory over the barbarians. If the slaves simply heap up uniform material found at ground level, and if the total weight of the finished mound is M, show that the work they...

I need to simulate the flow of a river, to do small scale hydrodynamics testing on a partially submerged water wheel / paddle wheel design. The typical water tunnel setup will not work, because we are interested in the flow near the surface. The water wheel is half in the water, and half out...

When exactly is one supposed to begin building relationships with their professors, and how? Thus far, I have not needed to interact with my professors beyond them merely lecturing me. I go, learn the material, write their tests, and that's the end of that. I understand that this is something...

I'm intending on creating a solenoid that will project a bb for a class project. I'm using a flash capacitor from a disposable camera as my current source. Here is my question...what is the best "setup" for the solenoid to increase the magnetic force on the bb without increasing its current...

Hey folks, I fancy myself as a bit of an audiophile. I love listening. I have a high-end audio interface on my computer with one set of outputs going to a pair of KRK studio monitors and a studio sub, and the other set of outputs going to some Klipsch Promedia general listening speakers...