Building Definition and 919 Threads

I need help building a motorized elliptical trammel, can someone help me? The idea is, I need to keep the basic design"educational", and keep the main purpose of it. I'll attach a photo of the basic idea...

To clarify, I'm not confused as to how massless strings can add up to make massive objects, I understand why that happens. My question has more to do with the speed at which strings move. If strings are massless, they must travel at the speed of light, correct? If so, then first off, what is the...

I have no clue on the first thing to start with. I want to make a remote that signals to a siren/alarm. 1) what kind of electronics/components would I need for a sensor. 2) how can I get it to connect to an alarm/siren sound? 3) where can I purchase the components to make this?

Homework Statement Homework Equations w = 1 / sqrt(LC) The Attempt at a Solution hi there, I 1. I decided to choose, 93.3 MHz so 93.3 x 10^6 Hz is my freq. 2. I googled how a band pass filter diagram should look like and I found this, is the only way to create a low...

I have three elements, A, B, C, that under certain conditions (rapid heating and cooling) form one ABC phase solid. Sometimes when I add a fourth element, D, I get two phase (AB,CD) solid. Obviously this phenomena is thermodynamically favourable. My guess (still undergraduate) is that there...

Homework Statement A stone dropped from the top of a building hits the ground in 2.9 s. How high is the building? a=9.8 m/s^2 yinitial=0 vinital=0 y=? Homework Equations y=1/2at^2 The Attempt at a Solution y=1/2at^2 Plugging in what I know: y=1/2(9.8m/s^2)(2.9s)^2...

Homework Statement which type of building is more likely to collapse, a building with tall walls or short walls. Homework Equations not sure, The Attempt at a Solution I know that this is a static equilibrium equation and common sense tells me that the taller the walls are, the more likely...

For example say you got an E_8 X E_8 heterotic string theory and you compactify it on a Calibi Yau with SU(3) holonomy it breaks one of the chiralities down to an E_6 G.U.T. So you have something like E_6 X E_8. What do you do with that other copy of E_8? How is that interpreted? I don't...

Hi, I decided to do a little weekend project and build an electromagnet. I read online to use copper wire and wrap it around an iron core. I was wondering If I could use anything other than iron, also, I hope you guys can tell me where I can commonly find the parts necessary for this project...

Does anyone have a good tutorial or start-up advice for building a database in Python? The only database software I've ever used is Microsoft Access, but I've heard it's possible to build databases in Python. I was thinking I'd start off with a simple database: a few tables that can draw...

Greetings Pfers I am curious what breakthroughs need to be made for the completion of a device capable of forming an atom out of the basic subatomic particles (protons, neutrons and electrons). Technology is advanced enough to where we have machines capable of generating these subatomic...

Hi all, We are trying to build a venturi and I have got a couple of questions. I am not an engineer actually, and I am working together with 2 mechanical engineers who graduated and forgot everything long time ago :) We are trying to build this venturi to collect hazelnuts from the...

Does anyone know which parts of the NEC (NFPA 70) are applicable when looking at converting a residential building to a commercial building. Such as converting homes into a buisness/offices.

I have been interested in constructing a vacuum chamber for quite some time, but I am not completely certain on what the structural specifications need to be so that it can hold up to the immense external pressure. My main motivation for building a chamber like this is in the hope that I will...

Homework Statement A baseball (radius = 0.0366m, mass = 0.145kg) is dropped from rest at the top of the Empire State Building (height = 1250ft = 381m). Calculate (a) the initial potential energy of the baseball, (b) its final kinetic energy, and (c) the total energy dissipated by the falling...

Homework Statement A boy throws a stone from the top of the building that is 45 m high. It lands 64 m away. Find the following: a) time of flight b) initial speed c) speed and angle with respect to the horizontal of the velocity vector at impact 2a) throwing the stone with more force (1.5...

I have been doing various experiments with my photography and recently built a coil gun. I simply pulled apart a starter-motor solenoid and wrapped the windings around an 8mm tube and fire a short piece of a bolt out of it using a charged 3300uf capacitor and an SCR. None of this is calculated...

My University just build this amazing library exclusively for the engineering departments and similar fields of study. This is my first time taking advantage of the new complex and I am sitting on the 3nd floor over an all glass-wall window. As the sun was setting I notice tiny popping noises on...

By using a bit of creative architecture! http://www.bbc.co.uk/news/uk-england-london-23930675

Homework Statement A small office unit is to contain 500 feet sq of floor space. (a) Express the length y of the building as a function of the width x. (b) If the walls cost $100 per running foot, express the cost C of the walls as a function of the width x. (Disregard the wall...

I always try to assume that pretty much anything I think of has been thought of before, so I am relatively sure that this is also not a new question. we base our current measurement systems on arbitrary lengths such as the meter or foot, etc. there are certain applications where we use...

i had a thought to stick two diodes together such that the electronic setup was similar to that of a BJT transistor. however i have been told by multiple teachers/professors that the two were not equivalent. I have drawn a picture to show you what i mean. the top two pictures are just the...

Alright, let's get down to business. How important is it for you to be the best and sexiest scientist. We may be spending a lot of time in the lab but how much time are we spending sculpting our bodies at the gym :wink: and the mirror every morning! Also, feel free to comment and...

Hi, I wanted to ask some questions about lasers. I'm pretty bored with school and want to work on a project for a while. I though of maybe trying to build a laser, mostly because it's really awesome, it sounds like a project that would be challenging but also teach me a lot, and it's sort of...

Homework Statement In the system shown, the strings and the pulleys are ideal. There is no friction anywhere in the system. As the system is released, block m1 moves downward. If the magnitude of the acceleration of block m1 is a, what is the magnitude of the acceleration of block m2?Homework...

How can I build a transmitter using radio waves with pulse modulation (Which I think [PM] means sine waves that either transmit or don't)? I can't find anything on how to build a PM transmitter, I can only find FM/AM ones, and I'm not smart enough to convert that information to the way I want...

I understand that this question has been asked before, but I've seen so many different formulas that I'm questioning which one is applicable to my situation. What are the correct formulas I need to build an alternator to meet certain requirements? I need to meet a specific voltage and amperage...

Hi, I'm interested in building a breadboard version of the simplest comparator using transistors and resistors. Ultimately I'd like to understand the LM393 but looking at the datasheet schematic, it seems quite complicated. I was hoping there was a simpler comparator I could mimic to start out...

Hi everyone. I'm looking to take up electronics as a hobby. I also play the electric bass guitar and I've been seriously contemplating building my own in my spare time. The ominous woodworking aside, I was wondering if anybody had any experience with building instrument electronics from...

Homework Statement Build a set notation for $$\bigcup_{i \in N}R × [i , i + 1]$$ The Attempt at a Solution ##\{(x,y) \in R : x \in R \ \ \exists z \in N \ \ z ≤ y ≤ (z+1)\}## Last time I tried one of these kind of sets I struggled quite a bit , so I'm interested in knowing how much...

Hi, I am interested in building a very primitive phased array radar for short ranges(1m to 100m). I thought it's possible to use a simple 2.4GHz RF ASK transmitter, and by just sending a single '1' bit I could generate a pulse and then use a simple RF receiver for that frequency and analyze the...

Homework Statement As an exercise , the book I'm reading ask me to build a set notation for the following set: ##\{... \ , \frac{1}{27} \ , \frac{1}{9} \ , \frac{1}{3} \ , 1 \ , 3 \ , 9 \ , 27 , \ ...\}## The Attempt at a Solution After playing with the numbers a couple of minutes , I came...

Homework Statement The book I'm reading ask me to build a set notation for the following set: ##\{-3/2 , -3/4 , 0 , 3/4 , 3/2 , 9/4 , 3 , 15/4 \}##. The Attempt at a Solution I attempted to build a set notation and came with the result: ##\{ x \in R : \exists y\in Z \ \ y(3/4)= x\}## My...

I am trying to build a radio to receive a 200 hz - 20 kHz signal. Can anyone give me a starting point as to what specific parts I would need (breadboard, operational amplifier, transistors, resistors, antennae, etc..)? The signal frequency is the most important thing for this project. Thanks...

I've had some bad trouble trying to create an electromagnet, so I've come here in hopes of help. Basically, I need to create an electromagnet strong enough to lift 2kg of weight. Because I don't know much on the subject, I have attempted this by wrapping insulated copper wire about an iron...

Well, I took my Physics final today, and I passed it but I didn't do quite as well as I'd hoped. Anyway, there was one problem I spent tons of time trying to figure out. I've tried giving it a shot again at home, but it's still eluding me. Some guidance would be great! Sorry if this is...

Hey guys.. I trying to build an magnet which can pull an object with 5N.. I am using S37 as my the iron for my horseshoe magnet, And been using this formula to convert Newtonian Force to magnetic force \vec{F}=\frac{B}{µ0}*A A= cross sectional area = 0,002*1/100 M^2 B = Magnetic Force...

hi, i assume this would be a structural engineer or an architect. i assume that an architect would have to have a good understanding of physics, especially when designing large buildings. i assume that there are regulations based on the historical performance of various construction...

So all my 3:8 decoders have outputs only at 1 and 0. I need a tristate decoder that can be configured so that the unused outputs are open circuits (i.e. high impedance). I know how to build a 3:8 decoder (using logic gates). How might I go about modifying it so that it has tristate outputs? Is...

Hello Guys, So I'm trying to build a database of organic compounds that are of interest to the pharmaceutical industry. Most importantly compounds containing heteroatoms (>= 15% by mass). Where do i start!? any good websites or books, with a useful appendix you can tell me about? I would...

Hello everyone, I'm very interested in building a cyclotron as a learning experience over the next year or so and have been doing some reading on what's required. I figure it would be helpful to ask everyone's opinion on materials such as electromagnets, beam detectors, vacuum cambers, etc. I'm...

I am building a prop for Aladdin's floating carpet. It will be a see-saw with the 2 characters on the carpet 300 lbs, 5 ft from fulcrum. 1500 ft lbs pressure. My question is how do I build a fulcrum 3 ft high, must have small footprint and movable. What is the torque on the pivot point,? how...

Hello, If there is a fixed noise like a faucet running, and I sit in a deskchair at a fixed location in an adjacent room, do you think it would be possible the build a program for either the desktop speaker (also fixed), or another computer somewhere else in the room which would cancel out...

I am working on an independent study that involves housing typologies and their adaptation to climatic conditions. I am looking at row housing and how their facades may become more adaptable and responsive to changes during storm conditions. My site is beach front and prone to hurricane/ cyclone...

Hello! I am currently looking into building a small hydrostatic pressure chamber to test the behaviour of a piece of tissue (cartilage) under physiological pressures. The pressure range should be between 5-15 MPa. I need to measure the volume change/deformation of the tissue, so the...

# -> means XOR ' => means NOT AB => means A and B A+B => means A or B Is it possible to build the following 3 functions F=(D#B)+(C#A) G=DCA'+DB'+CB'A' H=DC'B+D'C'A+D'BA+C'BA Using only 4 chips (Build all three functions using only 4 chips not 4 for each function) I have 8 switches...

Hi everyone, I am thinking of building up a new system to satisfy my need in scientific computing. My program usually involves with for-loop iterations written in Intel Visual Fortran 2013 on Microsoft Visual Studio 2010. Some of my work need to perform numerical methods, like Amoeba...

Hello everyone, I need to build a glider that can get from point A to B fastest. Point A is about 35ft off the ground, and Point B is about x = 190ft away from point A. I know the basic equation to consider here is L/D. I want this ratio to equal the (distance traveled/ascent lost)...

Hey guys, So I'm working on this project, and I'm trying to make two coils of different diameters to be tuned to the same resonance frequency. I got the equation ω=1/(LC)^0.5 for the frequency. My thinking was that the frequency of the wall power shouldn't matter because the resonance...

Homework Statement A friend of mine and me were walking through the city when he looked up at a tall building, let's say 25 metres, and said "I wonder how long it'd take to hit the ground if you jumped off". I was thinking about it and realized I didn't even know what the appropriate...