Material Definition and 1000 Threads

Dear Physicists, I am currently thinking of a way of inducing a current in a conducting material by a magnetic field. I am not good at magnetism and electricity at all, but I think it should look like the picture below. By the way, the material in the middle does not move. Does anyone...

I was wondering how long it takes to heat up materials. And how long will they hold their energy? Say for like thermal energy storage, how long does it take to heat up molten salts or other substances with sunlight? I guess I could just use Q=mcT and divide by time and then solve for time...

H-field depends on core material of toroid? If I got this right, the H-field does not depend on the material it is applied on and is only determined by its sources (free currents). So, suppose that we have a toroidal coil and some undefined core. As far as the H-filed is concerned, it would...

It just happened to me. And it's immensely frustrating. Not to mention the difficulty of convincing professors that I understand the material well (certainly well enough to get more than a 3.5 in it) despite getting below a 3.0 on the course. Yes, I made mistakes. My first few weeks were...

I've searched high and low among the vast archives of the internet and have yet to find any kind of formula regarding the magnetic field strength of ferromagnetic material (i.e bar magnet... etc). Does anyone know what/if there is one? As is B(r)=...? Thanks

Hello, I'm struggling to understand the exact conceptual difference between a flexo electric and peizo electric material. I mean, they seem more or less the same. could anyone please help me understand?

Assuming atoms pack together as hard spheres , find the largest intenstihal atom that can fit in a BCC arrangement of iron atoms . Take the radius of the irom atoms as 1,21 Å . Carry out the same calculations for an FCC arrangment of iron atoms . On the basis of these caluclation would you...

Homework Statement Suppose an unknown semiconductor material has bandgap energy of .1 eV. Density of states for conduction and valence bands are both = 10^18cm^-3. If the material is doped with shallow donors (n-type) Nd=10^17cm^-3, what is electron and hole concentrations? Homework...

I came into my engineering class this morning and our teacher showed us this strange material. He got the material from a student who recently went hiking. According to the student, he and his father went into the woods and started a fire in an old metal tire rim. They threw a bunch of old...

I am really struggling to get to grips with this question, ( struggling with material balance overall!) I can do dimple material balance however for things with a recycle stream or purge stream, really confuses me. I have the solution which I will post up, but I still don't get 'why' it...

hi, I am confused about how the vapor pressure affects the materials growth. Can someone comment on the following : If the vapor pressure of a precursor, let's say N, is high then it will be hard to grow a material containing N because it will be hard to incorporate it onto the substrate...

What is the ratio of graduates to job positions for graduates?

Homework Statement A cylinder with an open top is to be constructed with a predetermined volume of 1metre cube. the base of the cylinder is to be cut from a sqaure sheet of material, and the rest of the square sheet is to be discarded, find the dimension which minimize the material used...

Electric/magnetic field at point P in presence of dielectric/magnetic material. I want to confirm either the electric field at a point P in space in an \vec E_{ext} field with the presence of a dielectric material is the sum of the \vec E_{ext} and electric field \vec E_{p} from the...

Hi all, For a while now I have been searching for an electrically conductive material which is also UV transparent. Anyone here has come across such a material (solid or liquid) ? Thanks :)

I'm currently in IB SL Math (No HL here unfortunately), and I wish to learn more about contest-type mathematics as I have 3-4 contest here this year. Is there any books/materials that's useful for me? I have taken a look at this book: https://www.amazon.com/dp/0817645276/?tag=pfamazon01-20...

Homework Statement A sample consisting of potassium chlorate and an inert material is intensely heated. The weight loss observed is 20.0 %. What percentage of the sample is inert material? 2. The attempt at a solution I know when you heat potassium chlorate and another material, the...

I just want to verify that the dipole moment \vec{m} in the presence of external magnetic field \vec{B} will line up in the the same direction and parallel with the external field. This is according to the right hand rule that if magnetic field is the direction of the thumb, the current will...

I'm going to start working on developing thermoluminescence material by studying effects of impurities (at my university),, i need references as well as brief intuitive descriptions and things like that,, links to important papers on the subject will be appreciated as well.. thnx

I got A's in Intro Physics but after its now been a few years and I am reviewing this stuff so I will be better prepared. I am reading through an Intro Physics book but find that I have forgotten a lot of this stuff. I seemed to have retained a lot of the general ideas but am not doing...

I think it would be swell to have a sphere made of a clear, solid material that had the refractive index of air, because it would essentially be invisible. Is there anything even close to this?

I'm currently studying Agri. Mech. Eng but I need some help on this, I know roughly what to do but it's where to start: 1. Design a skimming boom for a biomass slurry transfer tank which can have a reach of 7.5m. Tool must attach to a "quick hitch" plate - factory spec for the loader is...

1. Homework Statement A substance has an isothermal compressibility k= (aT^3)/(P^2) and an expansivity B = (bT^2)/P where a and b are constants, T is temperature, P is pressure. Find the equation of state of the substance. 2. Homework Equations B= 1/v(dv/dT) (v is specific volume aka...

One of our teachers says that For two abjects of same material the following law must obeyd. i.e the ratios of their masses will be equal to the ration of their areas, wether this law works for objects of same shape or different? what is the name of this law? give me a link from which i...

I'm dropping a sphere from a known height, and it enters a viscous fluid. I know the initial velocity as it enters the fluid, from there I need the velocity as it falls through the fluid (as a function of time). I know it should approach it's settling velocity (terminal velocity) and from...

Hey guys, How do I create my own material in workbench? The material that I need is not available in engineering data. I have all the material properties that I need, just having hard time figuring that out. Thanks in advance

Anyone has backgroud on silicon material or VLSI engineering please sound off, I will pm you or please pm me advance. Thanks in advance.

So, a friend and I are writing the GRE physics in two months. We are both studying in Sweden where almost NOBODY ever writes the GRE, and none of my fellow students know what it is. There is therefore a great shortage of advice, experience, tips, standardized courses and material. Are...

Has anyone ever seen this stuff? In class the other day one of my professors moved the sliding chalkboards around to reveal the behind-most chalkboard. As he was writing/erasing you could see the board ripple suggesting it was made from a much thinner than normal chalkboard. I am getting sick...

Can you please provide some explanation for the following two questions? Or please provide some links. Thank you. 1.) How does a laser heat up a material? Does the material absorb a photon and the material's atom gets excited? - when the atom relaxes, it emit an energy equal to that of the...

Hi, I am developing a Ultrasound application where the sensor will be in contact with the skin but I can't use gel for accoustic coupling (or any liquid). Any ideas of materials (suppliers) for this purpose ? Thanks/Brgds Joao

Hi i want to study analytical mechanics. Should i read up on differential equations and linear algebra before starting on analytical mechanics? How about electromagnetism (beyond year 1 level)? Which is better to start, electromagnetism or analytical mechanics? And how about the math? Can...

Hi all, I'm attempting to get a feel for the different mechanical measures of a material, e.g., strength, toughness, stiffness, etc. I'm looking around, and I can't seem to figure out where a measure of stretchiness would fit in, that being how much a material will actually stretch or deform...

Unfortunately I have not been able to find anything reasonable online. I'd like an in depth all-inclusive explanation of IR transmitters and receivers, from a physical standpoint. I would also be glad to learn whatever else is included in the reading material, if anything. I have basic...

So i went to my first calc 2 class today, and i was lost =( i took calc 1 2 semesters ago and i don't remember anything (i got a B+ on calc 1) few students felt the same way, and ask the professor what to do, and his reply was "will you consider take calc1 again? Thats my best advise" But i...

You have 100 grams of radioactive material, how do i know the half life and the time i have 100 grams of material X. you do not know the half-life you do not know the time it started to decay what is its half-life/starting time? is this equation even solvable? if so, how?

Quantum theory says that the energy, E , (in eV) of a photon of wavelength λ is E = hc/eλ, where h is Planck's Constant, c is the velocity of light and e is the charge on an electron. Calculate the bandgap of a material which absorbs electrons shorter than 500nm.

A ray of light travels through a medium with an index of refraction n_{1} and strikes an layered medium such that the index of refraction is n_{2}=ky+1 where y is the depth of the medium and k is a constant. If it hits at an angle of \theta_{1} with respect to the normal, find the angle...

Eager young mind at work im trying to come up with a concept of a suit that you ware at work, the main purpose is to let you have in on (like a uniform) but with a different design and material i have done some research but let's face it unless there is a different browser out there that I am...

Hi everyone, Can anyone suggest a raw material that has the properties similar to steel and produce less noise when meshing with other part. I thought of polymers like Cast nylon, HDPE etc, but the issue is, it has to withstand a temp of around 200°C, during working condition. Thanks...

I have a hat, made from what I believe is rabbit hair (not leather, just the hair). I sometimes leave it in the car. I have noticed that if I leave it in the car for a long period, when it is hot, the hat shrinks. I have 2 questions. A. Why does this shrinking happen? B. Is there any way to...

i was trying to look for which forum to put this in so sorry if its in the wrong one. :D Im working on a project and i need a material that is able to reflect radio waves, like a mirror reflects light. any ideas for which material will reflect?

Homework Statement A block of material with a cross sectional area of 15cm^2 and length of 8cm is at hand. A temperature difference of 30degrees is established and maintained across the block. Find the rate of heat flow through it if the material is wood (K = 0.08Js-1m-1C-1) Homework...

Hi there, This may sound like a silly question, but I'm looking at shining a high power laser onto a target material for a fixed period of time. I have modeled Alumina in Ansys Icepak, and the temperature increase has come to 4700 degrees C. This maximum temperature is only reached for...

let me explain i do a static tensile test and get the stress strain graph. the area under the graph is the toughness that means i can use this static toughness data to predict the failure under impact loads other idea is that i have done a impact toughess test. if i can get the...

I am an electrical engineer and not familiar with this. I need to look up the permittivity and conductivity, density and acoustic speed of some common fluids: sea water, de-ionized water, castor oil, alchohol, ... Where would I find some reference containing these numbers? Thank you.

i have found the damping factor of a plate from experimental vibration. how can i find the damping coefficient of the material of the plate

I have an application where I have a shaft being supported from end to end with bearings (self aligning) and a motor hard mounted driving it. The shaft starts at 1 3/4" RD to accept motor and bearings. Then is welded to a 2" x 1/4" square tube for the output. It allows for a wooden roller to be...

What is the most corrosion resistant alloy other than Zirconium and SS that could be used in reactors but it is not economical?

Hi, I'll be starting a physics major in the fall at university. I was wondering, is there any good reading material I can get my hands on so I can start learning now? Thanks.