Strength Definition and 1000 Threads

Could somebody check my solution?

I am trying to design an electromagnet which consists of a copper PVC sheathed wire wound around a cylindrical plastic spool of Circumference (C) = pi x diameter. The spool has a hollow body of diameter D1. This wire has maximum length (L), cross sectional area A, resistivity P. The spool once...

It seems a gravitational field does not alter the electromagnetic field strength. Is this correct? My reasoning: With no gravity, field strength is: F_{\mu\nu} = \partial_\mu A_\nu - \partial_\nu A_\mu Introduce gravity: \partial_\mu A_\nu \rightarrow \nabla_\mu A_\nu = \partial_\mu A_\nu +...

Hi, in mechanics of materials books one may easily find fomulas for stress and strain in thin- and thick-walled cylindrical pressure vessels subjected to internal pressure. However, it is assumed that they are open. So what are the formulas for stress and strain in capped vessels (with flat or...

The answer learned in class is that the two 2*4s are able to distribute the load over both of them, but I don't think this is an actual answer because that's balanced by the fact that each block is half the area. Does anyone know of the reason for this observation? Thanks!

I would assume that because the samples are made of the same material they would fail at the same stress and so the same strain. However, the data shows that the sample with a greater cross-sectional area fails at a greater strain, and the two are roughly proportional. Does anyone know what...

1. The centripetal force is equal to F= mv^2/r. The velocity of the Earth can be found by: V=2πr/T T=1 day = 24 hr*60min*60sec=86400 s v=2π*6.4 x 10^6/86400 s v=465.4211 ... ~465 ms^-1 to 3.s.f Therefore, F=1*465/6.4 x 10^6 F=98/1280000=7.265626 *10^-5 ~7.3 *10^-5 N Would this be correct since...

I'm using the wikipedia page on Size Effect to get an understanding of it. It identifies Statistical and Energetic size effects and two types within energetic. I believe I understand statistical, as it seems to essentially say that assuming there's some variation in the material strength, the...

I'm considering building a microlight aircraft from a set of plans. According to the plans the wing spar required is a 6m long rectangular box section 100mm x 50mm with wall thickness of 2mm, it is made of aluminium grade 6060 T5. I'm struggling to source a suitable piece of aluminium so was...

I am doing a book that have only exercises, and an introduction to the posterior theme, so, in the introduction, there is the relevant equations, and there is a equation: G = -Gm/r^3 called strength G, in the gravitational topic, what is this? I never saw it.

I have a dc magnet which use in scrap yard and the only perameter I know is ,it consume 50 to 70 amps and it area , 440 ac input supply .now I want to know how iron scrap it can lift?

What is the strongest actuator (that can exert a controlled amount of force & be able to start/stop linearly or rotationally) that an infinitely advanced civilization could create, and how (what object/process) would they do it? It must be non-lethal or be shielded to be non-lethal at a distance...

Well, I have one nice problem. I have 30x10mm busbar, and Isc=30kA. I must place this busbars in electrical panel, but I have a problem with insulators. Can I use a red insolators as it's showed on picture, or I should use special holders for busbar system. Another problem is: When I use such...

Hello there, I'm currently studying shear and compression. I am wondering, in my textbook, it says that most bone fractures are not caused by compression but by twisting or bending?? I mean bone's shear modulus is as great as that of a steel's, but its young modulus is far smaller than its...

Hi all, I was hoping a guy with limited engineering skills might find a little help and understanding... I'm not formally trained but am somewhat mechanically inclined. I build things, and usually have good luck estimating strengths and designing things without doing the math or science behind...

I'm an angler and having extensive discussions on a fishing forum about the properties of monofilament fishing line. There are two forms: various nylons - mainly we think PA6 and PA66 - and fluorocarbon. Our experience and 'garage testing' of these lines tell us that fluorocarbon while it can...

Given the example g = \frac{GM}{R^{2}}, we may compute the change in field strength if the mass is changed by a small amount dM to be$$dg = \frac{G dM}{R^{2}}$$and also if R is changed by dR,$$dg = \frac{-2 GM dR}{R^{3}}$$If, however, both the mass and radius are changed by a small amount at the...

Hello, I'm in the process of building a 2 story townhome project and had a question on a beam. The structural engineer is calling for a cut I-beam on top foundation which spans over the garage (10') and the load will be placed on just the top flange (see attached). The structure will cantilever...

Details of this calculation from the photo?

Lenght=300mm, Force at the end of the handlebar is 200N What i would like to know is: does that 20x20mm end piece affect the calculation process in any way? and whether there are more than 3 types of stresses in this case. First stress being moment created by the 200N and second stress is shear...

Hi, So,I'm helping a guy with his mechanical engineering homework. The problem is that the guy is so off, he doesn't even know the name of the subject. And honestly, I having a hard question finding out what this question is about. I need to proove the Zb=h^2/3 thingy. I have no idea what this...

Hello, Today I am wondering if anyone can help me quantify the strength of the magnetic field created by a permanent cylindrical magnet. I have been able to find equations online for the strength of the field within the z axis, (ie. the longitudinal length) but I would like to know the strength...

https://en.wikipedia.org/wiki/Size_effect_on_structural_strength#cite_note-1 I don't understand about non-random strength (f_t) and size effect of material And please explain to me for the size effect? :cry::cry::cry::cry::cry:

Dear community, I am an electrical engineer trying to make my hobby four seater car. Being not a mechanical guy I am really uncertain of the chassis design that I have concepted though with the help of a friend we got some basic simulation running. My concept is to use a standard rectangular...

For reference, this is from Griffiths, introduction to quantum mechanics electrodynamics, p253-255 When deriving the ideal magnetic dipole field strength, if we put the moment m at origin and make it parallel to the z-axis, the book went from the vector potential A $$ A=...

As you can see in the pictures below the trucks are attached to the skateboard with four screws nuts and bolts, with a 2~3mm piece of rubber between the truck and the board. I've always wondered if tightening the screws bolts harder, decreases or increases the strength of the 7-layered plywood...

So I've been looking at a few material tests and they all start with a rectangular sample of the material, loaded into a machine which extends them by increasing load at a constant rate and measures the strain/stress till the point of material fracture. The yield stress is measured in usually...

Summary: I want to crush a single layer of granules from a single material that are 400-600um in size using a flat, circular probe, which will generate a force v time or force v distance curve. The quantity I am trying to measure is the granule (tensile) strength of the material. I believe...

Also how bullet proof is it? I know it is a titanium nickel alloy so I’m guessing it may be strong with the titanium in it.

Summary: Yield Strength value as well as maximum load capacity. Need equations and possibly a break down on how to solve the issue. So let's say I have a Wooden Street pole and I want to mount a steel bracket using metal bands to the street pole. The bracket will be mounted to the beam using 4...

I'm trying to learn some new engineering, so if something I ask doesn't make sense -- remember I'm new to this. I need to calculate how much force a part can take before breaking. Material: resin (Flexural Yield Strength: 6752 psi) - (Tensile Strength: 3390 psi) - (Density [lbs/gal]: 9.64) -...

Hi, I've found this property of Strenght Field Tensors: $$F_{\mu}^{\nu}\tilde{F}_{\nu}^{\lambda}=-\frac{1}{4}\delta_{\mu}^{\lambda}F^{\alpha\beta}\tilde{F}_{\alpha\beta}$$ Where $$\tilde{F}_{\mu\nu}=\frac{1}{2}\varepsilon_{\mu\nu\alpha\beta}F^{\alpha\beta}, \qquad \varepsilon_{0123}=1$$ I've...

I'm planning on making marquee poles out of aluminium tube. I did so last year and they worked well, but they flexed slightly under tension. To correct this flex, I want to use slightly different size of aluminum tube. I used 4" tube, with a ¼" wall, at a length of 30'. Will the tube be...

V=I*R 6v=I*(0.6+0.9)ohms I=4amp B=100*(uo)(2N)(I)/L * 1/2 I think since the wire is double wrapped, we multiply the equation by 2, but since we are looking for the magnetic field at the end of the wire we also have to multiply the equation by 1/2 I=4A, uo= 4pi*10^-7 2N/L turns per unit...

Hi all, I would need an high dielectric strenght glue to fix PTFE or Hostaphan to the vacuum chamber wall in stainless steel, so the glue should be vacuum compatible. Force against the bonding direction would be 50N, so if the glue has already 100N it would be good but I don't think it is an...

Based on dimensions and the materials' Young's modulus, I know how to calculate the expected deflection of a rectangular sheet of material under a given distributed or point load and given various edge support conditions. I have discovered however that multiple thinner sheets when bonded...

HI guys, I am in the middle of a project where i have 3d printed ABS & PLA spur gears, I am looking to do gear teeth strength calculations however I am not sure how to apply the formulas. This is because of the layered structure and the infill % of the prints. Ill appreciate all help. Thank you

Hello! I would need advice on insulator material I can use for an ion Thomson Parabola spectrometer. I would need to use an insulating sheet of 225x600x1,5mm and a smaller sheet of 100x100x1,5mm I found PBN having an incredible dielctric strength, but seems like it cannot be manufactured in...

So I see EM radiation , visible spectrum including being portrayed as two sinewave vectors each perpendicular to other one being that of the E field the other being the B field, the field is carried by photons, let's take the visible spectrum as an example. So having a specific frequency the...

I'm trying to find the Yield strength, that is how much force can be applied to carbon nanotubes so that they stretch to the limit before plastic deformation. And also how much they stretch at this limit. Do they stretch at all? Or are they always the same length until the Ultimate Tensile...

Hello! I am in a student-run engineering team that heavily utilizes fiber reinforced plastics, and I am just trying to get a better understanding of FRPs. I am wondering how exactly the fiber reinforces the plastic. Let's say the yield strength of the fiber in the 0 degree tensile direction is...

Have there been any measurements of the strong force? Also its curve of the strength of the force vs distance

Homework Statement There are four things to be calculated: -pH of 0.00196M solution of HCl in water, without taking ionic strength into account, -The same thing but taking ionic strength into account -pH of 0.00196M solution of HCl in Na2SO4, without taking ionic strength into account, -And...

Keplerians, 1 of my humanoid species, are so strong, they can carry a bear with just their muscles. Humanoid weight: 200 lbs with a lot of muscle mass Black bear weight: up to 600 lbs, also very muscular That means they can carry up to 3x their weight. That is very strong. But would this...

Hi all I was hoping someone could shed some light on the following:- I am trying to understand what Yield strength is and understand the exact limit of where elastic and plastic deformation occurs on a stress strain curve. Correct me if I am wrong but I define:- Yield strength as the amount...

This relates to the anthropic principle and the multiverse. Nuclear Processes in Other Universes: Varying the Strength of the Weak Force https://journals.aps.org/prd/pdf/10.1103/PhysRevD.98.063014 Nuclear processes in other universes: Varying the strength of the weak force Alex R. Howe, Evan...

Hi There is a story that Enrico Fermi calculated the intensity of the first nuclear test at Los Alamos from the distance moved by scraps of paper. Are there documented details of the calculation in any paper / book ? TIA

Homework Statement [/B] I am working on a experiment on finding the Earth's magnetic field strength in Denmark. Using a Galvanometer and a constant power source of 5.1V and slowly adjusting the resistance, I was able to find the changes in angle in relation to the changes of current. 2...

Hi, I have a quick question. Say I have two metal rods or tubes and I want to make an electromagnet, one rod is with a diameter x and the other rod has a diameter of x2 (two times larger) Now I take the same gauge copper wire and wrap an equal amount of turns around each of the two rods. Then I...