Building Definition and 919 Threads

Maybe 1860s - 1870s tintype. Post processed heavily to reveal the image. What do you think they are building? I'm not student or engineer. I'm an archivist. (non-professional) I get lots of old photos and films that need some deciphering, so hope this group can help out.

I am among other things a farmer who is getting older and having a harder time using my hands. My current project is to make fruit picking easier for myself. Over the years I have built homes, designed and built aluminum fishing boats in Alaska, Banjo's and guitars.

I need to build a robotic vacuum cleaner that requires minimally 20kPa suction pressure, and is able to clean a 1000sqft area within a single charge of the battery. How do I first calculate the motor specs required to produce that suction pressure and the battery that is able to last the entire...

Sets are called the building block of maths, but why? To me sets are a collection of 'things'. Were as numbers are what give the 'things' a meaning. Myself I think that addition is the building block and maybe subtraction, all the other processes, addition and division are only quick ways of...

I'm looking to compile a large online database of physics formulas*. I have yet to find any comprehensive "physics list" that isn't too domain specific or simply scalable. My attempt will be to build it here newtondb.com following and expanding on pldb.com. It will be built using a treebase...

TL;DR Summary: Mechanical engineering,robotics,mechnics,dynamics Hi guys , I'm new to mechnics and I want to learn it for building robotic arm , but I find mechanics book topics somewhat difficult for me , what I need to learn to get started as I'm a highschool student with basic level math.

Hii i have design PCB Board and i have solder components i have given input Vin=32V and Vout= 12V but i am getting Vout= 29V. Please check any changes in my schematic.

I am researching self-learning AI, and one of the most talked of solutions is returning to analog computing. Analog computing uses real time changes in voltage and frequency to run calculations or perform functions. Does anyone have any experience in building electronic analog computers based on...

MENTOR Note: Post moved from General Discussion to Aerospace Engineering How did you find PF?: I found PF because of a late night idea I had when I was bored, but I have no idea how to do it so I was looking up information when I came across this app. I'm sure most of you guys on here know...

TL;DR Summary: Seeking good simulations to build my intuition Hi everyone, I am currently teaching myself classical mechanics, and am 3/4 of the way through "Vibrations and Waves," a textbook from 1971 which was used in the MIT course. It's going okay - I feel like I have a decent grasp of...

Hi all, I'd like to make an home-built OD600 sensor for measurement of cell concentration in suspension by Optical Density. There are several spectrophotometers in the market, indeed quite expensive, so I am interested in realizing a cheap device with standard components. Here's an example on...

I moved to Kansas from Arkansas when my father got a job at the Sunflower Army Ammunition Plant in Desoto Kansas. Now that plant will be making Batteries for electric autos. I wish my dad was still alive to see this.

Hello, I attend a physics club at my school and now, we are building rockets until winter. I need some help because I really want to beat the GCSE students. We are in self chosen teams and the winner is who gets their rocket the highest(hopefully it will go high enough so we can't see it) I have...

I'm doing self-study out of a free .PDF book entitled, Trigonometry, by Richard W. Beveridge (©June 18, 2014). The problem I'm interested in is as follows: "A woman standing on a hill sees a building that she knows is 55 feet tall. The angle of depression to the bottom of the building is 27°...

Basically what I need is to figure out what motors I need for a design I am wanting to make for an electric motorcycle. I know that I want it to go around 60-70 mph, 60 could be the max speed if need be, for the motors to be able to move 700 lbs (which is crazy but my idea is crazy so I need it...

Hi, I mostly do Self study and I was wondering how to build up a course ie the.different levels from beginner to advanced in the fields of linear algebra, optimization (rbfs etc), statistics and probability? Suggestions of books with the various levels is welcome. Please help me out in this as...

As stated in the summary, I'd like to design a chamber to store water under pressure. Nothing too powerful - basically at the level of a super soaker, maybe a little higher. The trick is, I want it to be powered and controlled electronically. But, I come from electronics land and know nothing...

Hey'all. First of all, I'm not fluent in English, so forgive me for the spelling mistakes. So, I'm trying to make a simulation of a solar system using python 3.9. It's not complicated, but my teacher wants me to do it using the Basic Verlet method, and that's what is bugging me. He told me do do...

Hi, I have this kinematics question I am struggling with. There is a building from which a ball is dropped and it takes 5 second to reach the ground. Then they say that the same building is on a planet w/o atmosphere where g= 6 m/s^2 . What is the height of the building ? I approached this...

Good morning Thank you very much for being part of this forum. I have a concern. I have 4 D2059 transistors and I want to build an audio amplifier, but I don't have enough knowledge of electronics. And I have one more transistor tip117. Can anyone help me by sending a simple circuit diagram how...

Hypothetically how can someone build a small hot air balloon? I want to navigate a 360 camera to the air without needing a drone. Just a balloon, camera, and string to keep it from getting away. Maybe a remote fan to pull it down if string gets loose.

A science teacher ask if I could help one of her students build a "Time Dilation Clock" so, at launch the Ships chronometer and the local time are in sync. with a 3g continuous thrust, at some point the time, the time at the launch site will be going twice as fast as the ships chronometer. so...

Summary:: A 90 kg firefighter needs to climb the stairs of a 20-m-tall building while carrying 40kg of gear. How much power does he need to reach the top of the building in 55s. So first the total mass of our system is 130 kg. Using this mass, I found the potential energy the firefighter would...

Hi, has anyone tried to build "quantum GR", using the expectation value of |Psi(x)> as a "quantum ruler" and |Psi(t)> as a "quantum clock" to build up the idea of a "quantum metric"?

Alright, time to get started on what I joined this forum for a few days ago: Checking the plausibility of the worldbuilding for my story about a generation ship. Specifically, one with falling birth rates - on its slide into totalitarianism as a result. ;) The main character is a 24-year-old...

Hi Everyone - I found a previous post here that has helped me size an engine for a ski tow rope but wanted to take that a step further an add friction into the equation. If I followed that problem corrected, the tow rope requires 821W calculated as follows: power = work/time...

Summary:: My back wheel spins when in the air, but won't when on the ground, help! My car has two four inch wood wheels on the front and a 12 inch wood wheel on the back, they are securely attached to the axel and I have 1/2 inch ball bearings to connect the axel to the frame. My lever arm is...

Hello! I am trying to build an optical cavity and I am having some issues with vibrations. I attached below a plot of the acceleration in x, y and z as a function of time, when the accelerometer is placed on the optical plate (x is red, y is green and z is blue; I shifted them upwards for...

I am trying to build a dual input (double input) crankshaft, out of Lego. All the tutorials online use flywheels, but I want a strong high quality crankshaft that doesn't rely on flywheels. The crankshaft is for a 1 cylinder or sinusoidal linear type input. This video demonstrates the flaw of...

(USA) building codes require that wires that are spliced together must be contained in electrical boxes that are accessible - e.g. you can't splice together wires in an attic. So one often finds electrical boxes for ceiling fans or electrical outlets also serving as junction boxes in the sense...

Hi! I am an engineering graduate that took my bachelor's degree in Mechanical Engineering much too long ago, but I have forgotten a lot of the classical mechanics/mechanics of materials theory that I had learned many years ago. I am building a motorcycle right now, and I want to calculate the...

My dad has been asking about some speakers for his boat, something that will move a bit of air, not too big though. I'm thinking 1x12. He also wants it bluetooth and powered externally, so it doesn't drain the boat battery. So I'm thinking 1x12 speaker in a small box that can fit inside the...

Hi, I am trying to use an LT1170 to convert between 25-50 Vin to 5 Vout. Actually, I would like to keep a constant 5 V out regardless of the input. To do that I know the input would have to be 5 V plus any voltage drops with a 100% duty cycle but it's going to be low current so large duty cycles...

I tried to write to the code, but I got confused in line 46 & 59.Every new added bus increases the dimension of the Z matrix, and since we have 3 busses, the dimension of Z should be [3x3]. I formed a for loop in case of adding a new bus to add a new row and new column (increases the...

Summary:: What is the important thing to consider a factor for build a house ? I am a civil engineering student and I have a question about What is the important thing to consider a factor for build a house ?

Hello. I posted this last night and after two people replied commenting on regulations, the thread was closed because it was resolved. It wasn't. So I'll post it again but this time I'll start with a comment about the replies I got on the other thread to which I couldn't answer back. I know...

Hi, everyone, this is my first time here. I've been looking for hours and can't find the information/formulas to figure this out, that's why I came. I'm building a roof for the backyard (workshop) so I can work all year regardless of weather conditions. I know what materials and dimensions I...

I know string theory is already controversial enough and may even be falling out of favor among many physicists. But assuming it is right, I have heard string theorists say that strings are the "fundamental building block" of the universe. How do they make this assertion so confidently...

Hello, I am in the process of building an over head hoist in my shop.I've already taken delivery of the metal, so I hope I erred on the side of safety. I am spanning 20' and will be using a 1/2 ton electric hoist and trolly. I found a chart online from Harrington Crane Co. That specified that a...

I want to work on a personal project, a web application similar to PhysicsForums just to understand how everything works. I have some basic questions. 1. What kind of database is ideal for a discussion forum like this ? SQL or NoSQL ? 2. Which frontend and backend technologies are used to...

How can I make progress in studies? What happens to me is that if my friend gets very good marks then I work very hard to achieve marks but problem is that i can't stay consistent,like today i have given test and i called my friend to know his scores and he told me that he has got scores...

I want to build a cheap, portable water level recorder so I can record the "seiche" on my lake (and other lakes). I don't want to use fancy components like Arduino boards. And I want it to be portable (and cheap enough that losing it to water, weather or thieves won't be a heartbreak.) There's...

So I got this question while coming across, and I would like to seek some advice/tips for these types of questions. 1) Assuming I want to try and build using MUXs, I will get the truth table of both a 2 bit comparator and MUXs. In this case: For comparator: And for MUX: So from what I...

Buildings A and B are across the street from each other, 35m apart. From a point on the roof of Building A, the angle of elevation to the top of Building B is 24°, and the angle of depression of the base of Building B is 34°. How tall is each building? Let x = height of building A. tan(34°) =...

https://www.zdnet.com/article/a-student-has-rebuilt-the-machine-that-first-cracked-german-enigma-codes/

Hello. I am building a three phase motor for a science project of mine. I am trying to match my motor with an inverter so i need to count how many poles I have in this motor. The problem is that I have read about this and some people say that this...

Hello all, I am a college student from the UK and as part of my course i have to do a project, I have been given a project to do which is to Design a portable electronics circuit that can be used for training. It must be; Able to measure current, voltage and resistance. Operate on 10 Volts DC...

So far I have an R928 Hamamatsu pmt from ebay, that I believe will be good since it has UV glass, and the majority of the photons should be in the UV range. I also have an old Brandenburg pmt HV power supply but need a BNC connector to use it. I already have a good rigol oscilloscope. Soon I...

I want to solve the following system of equations ##M_{1} = f_1+f_2+m_1+m_2\ \ ;\ \ M_{7} = f_1+f_2+s_1+s_2\ \ ;\ \ M_{13} = m_1+m_2+s_1+s_2## ##M_{2} = f_1+f_3+m_1+m_3\ \ ;\ \ M_{8} = f_1+f_3+s_1+s_3\ \ ;\ \ M_{14} = m_1+m_3+s_1+s_3## ##M_{3} = f_1+f_4+m_1+m_4\ \ ;\ \ M_{9} = f_1+f_4+s_1+s_4\...

Building jig for a project, trying to think of ISO that would apply. So far i got ISO 8888 ISO 10377 ISO 14990 ISO MADECan somebody help