Materials Definition and 989 Threads

Anybody knows if there is a rule for EM radiation cross over materials ? The wavelenght in comparison the size (or structure) of molecule is determinant ? Ex. why infrared pass through the concrete but not metalics ? Thank you.

Materials -- unit cell question "In terms of the atomic radius, R, determine the distance between the centers of adjacent atoms for the BCC crystal structure along the [111] direction." I got the answer 4R but it is wrong. I came up with this by assuming that atoms touch each other in the...

Ok I feel this is the best place to place this subject. Well, I have been interested in materials science and crystallography lately, especially the future applications of this. What are some future materials we could make from studying crystal growth? How could we go about accomplishing this...

Hi, any idea , what is the material inside a internal combustion engine need to be change when i change the gasoline fuel into hydrogen fuel.? Also what is the lubricant that will suitable for this hydrogen fuel. thanks Piston top - what is the suitable material Cylinder head-...

Greetings and happy new year to all members in here. This is my first post in the physics forum. Does anyone know what sort of materials are commonly used to make the steelframes of car? I am guessing it's some form of steel, but which? And why the choice? For illustration, the link...

And what's the job outlook / salary of one? Thanks in advance.

Hi I wonder if you could help a really thick oldie with a problem, I found this:- I need to build a set of ramps for my dump trailer. The ramps will be 6' long. I have and want to use 1" x 3" 11 gauge rectangular steel. If I were to take one 6' piece of this material, stand it on its'...

My interest is in reducing RF interference in electric guitars in RF-noisy environments by shielding the body cavities with sheet metal. Would copper sheeting block RF? Or would it need to be some ferric material? I imagine aluminum alloy would be RF-transparent - is that true? Ideally, I...

Homework Statement Hospital operating theatres, floors are made out of conducting material and staff wear shoes made of conducting material not insulating material. How sis charge built up on insulating soles and how does using conducting material reduce charge & sparks? Homework...

Or does it depend on which area of condensed physics one is specializing in?

Hello everybody, I've just graduated ( this summer ) from the University of Bucharest with a BEng degree in Technical Physics. I'm currently pursuing a masters degree in the physics of atomes and molecules at the same university. I'm also working in a research institute part of a group...

Seeing that a Materials Science undergrad degree isn't offered many places, what's the next best major? The substitutions, to me, vary drastically. I've seen Chemical Engineering, Mechanical Engineering, or Physics as substitutes. I think Magnets and Condensed Matter are neato, if that helps...

Homework Statement hello I have to make a concrete base in metres cubed total 1.68 metres cubed. The ratio to concrete is 1 part cement to 2 parts sand and 3 parts gravel. how much cement,gravel, and sand in kilograms? Homework Equations ? The Attempt at a Solution ?

Hello, I am a physics master student and I have to present a talk about The Nuclei(its constituents, models, decays and radiation). I am searching the internet about useful graphics and materials, it seems to me hard to get appropriate ones! please post any web links that may help...

A cautious hello to the forum :) Im seeking a tool for selecting materials for a given application. Im a mechanical eng. student so my real world experience is limited. For example: Shaft D=3mm l=500mm torque applied = 0.25Nm Must be weather-resistant Given this information...

hi everbody.. i graduated form metallurgy and metarials engineering.. ı want to do my master degree..l've been having trouble choosing the field.. i m intersted in carbon fibers about textile.. but ı didnt take any class for this material.. so what u think carbon fibers ın textile will be...

I am trying to use the Bethe-Bloch equation to investigate how a Muon loses its energy as it penetrates through different materials in the muon lifetime experiment. In order to do so I need 2 determine both the total energy and kinetic energy. For kinetic energy maximum I have been using Tmx...

Hi guys, I am attaching a pdf file with the respective question it might be silly for many of you, but I would rather this question now, and move on with the problem. The pdf file is from a class from mechanics of materials, I understand the procedure and how formulas are plugged and how the...

I'm currently in my second year of undergrad doing a degree in Materials Science and Engineering. From career fairs and other students, I found out that not that many companies are recruiting for my major. I'm specializing in electronic materials so I'm taking electrical engineering courses in...

Hi All, Could someone share their opinions and analysis on the future trends of engineering industries, such as the growing potential, job demands and salary competitiveness of different engineering fields? (EE, ME, CE, AE, SE) If you could, please be specific to the sub-discipline. (Example...

Would anybody know the following or be able to point me to a web resource? Thanks Do you know of any materials that retain some elasticity at cryogenic temperatures in the 20 degrees Kelvin range? This would be for a bladder that would hold liquid nitrogen in a bath of liquid Hydrogen or...

Hello! I am a junior in a high school. Currently, I am exploring different different colleges and universities, only in the United States and America. Right now, materials science and polymer chemistry is really interests me and I want to know if anyone here can recommend a university...

what factors affect materials behaviour? what factors affect materials behaviour? help me please...

I posted this in a different board, but I think this is a better place, so I'm reposting. I'm taking a materials science class (in Korea) but I'd like a decent English-language textbook to supplement the class-recommended material. The specific class name in English is "MECHANICAL BEHAVIOR...

Why does light travel at varying speeds through different materials?? why does light travel at different speeds through different materials?? for example, it travels at 38 mph through super cooled sodium. also, if light is massless, why is it susceptible to gravity?? i don't know the...

Hi all, I've finished a hypothetical problem in which I have determined the optimum damping ratio $\zeta$ for a specific system. This $\zeta$ value (0.265 in my case) minimizes the peak force transmitted through an object. My next step is to take this $\zeta$ value and find some sort of...

Seatwork no. 1 -------Strength of Materials---------- The 20 mm diameter bolt fastens two wooden planks together. The nut is tightened until the tensile stress in the bolt is 150 Mpa. Find the smallest safe diameter “d” of the washers, if the working bearing stress for wood is 13 Mpa...

Prefferably the strongest for the lowest price :D

i have got 3 questions... What is material property orientation in orthotropic materials...in what way it differs from material distribution with respect to two or three planes?..and how does it affect the material behaviour?

If someone unknowlingly touch a radioactive substance or source, would their skin or hands then be radioactive? And also-could you spread contamination if you touched a solid source? or it could only spread in powder form? what is the likelihood of becoming contaminated by a source for a normal...

I know this will sound nuts, because it kind of is, but I though maybe someone could talk some sense into me. I suffer from ocd and irrational fears about radioactive substances. I realize that we are surrounded by and constantly bombarded by radiation. That doesn't bother me. Nor does having...

Dear All, I am looking some meterials on Gas behaviour on the heat, like boiling point, density factors and other. Please advice me on the training materials regarding to this. Thanks in advance Jaykar N

I have a problem understanding what is going wrong with a simple derivation for strain energy. Problem: Assume a prismatic bar of length L where the elastic region is assumed. If it is hanging vertically its own weight produces some strain. If all the work goes into strain energy the...

[SOLVED] Parallel-plate capacitor: Two dielectric materials Homework Statement A parallel-plate capacitor with area A = 5.56 cm^2 and separation d = 5.56 mm has the left half of the gap filled with material of dielectric constant K1 = 7.00 and the right half filled with material of...

Here's one for the McGyvers amongst you. Let's suppose we want to power a model-aeroplane that runs on a mixture of gasoline, plus nitromethane. Leaving the gasoline aside because we have plenty, the challenge is: Can the nitromethane be home-made? Ie from household materials, like...

[SOLVED] Snells Law (Changing view of an object through different materials) Homework Statement A shallow glass dish is 4.0cm wide at the bottom, as shown in the attached figure. When at observer's eye is positioned as shown, the observer sees the edge of the bottom of the empty dish. When...

This material forms a bridge between mechanics and materials science. MIT Open Course - http://ocw.mit.edu/OcwWeb/Materials-Science-and-Engineering/3-11Mechanics-of-MaterialsFall1999/Modules/index.htm This is a fairly general course. A more specialized area - DEFORMATION-MECHANISM...

I'm interested in chemistry right now, even though I haven't taken a chemistry course in two years and my school would not allow me to take first semester chemistry for credit again because I have taken it in high school at another college. Now I am thinking of whether do chemistry or materials...

Hello everyone. Does anyone know of a good hobby/educational store that sells stuff you can use in physics fair demonstrations? Specifically, I am looking to buy a gyroscope. Although it's a popular toy, they've been hard to find (and due to budget and time constraints I'd rather not order one...

Currently, I'm an undergraduate majoring in Physics in America, and I want to get my masters in materials engineering in Israel (which works on the European education system--aaack!) Does anyone have any ideas what sort of pre-requisites I'll need? By the time I graduate I will have taken...

Hey guys, I'm a second year Electronics Engineering undergrad student and this semester I'm studying a subject called Communications Engineering 1, which is basically an introduction to Digital and Analogue Communications. I'm really stuck so far on the Analogue stuff because our lecture...

I was at a high school science symposium, and some kid presented about metamaterials, a structure that shows a negative index of refraction, n. So I think his project was pretty good and all, and he had a good understanding: he had apparently created a new composite structure with neg. n without...

why some materials reflect light more than others?

Hello, Why can some waves pass through materials but others can't. Why can visible light go through glass but infrared can't? I know it has to do with transmission but what is the fundamental processes? In as simple terms as possible? If anyone has any websites of books that might help please...

Homework Statement Two wires each of 2.50m long, one of steel of diameter 1.0mm and the other of copper of diameter 0.56mm are suspended from two points in the same horizontal plane 200mm apart. The lower ends of the wires are fixed to the two ends of a uniform bar 200mm long and of weight...

why some materials bounce off more than the others? What happens with the microstructure?

why some materials have bigger refractive index than others? Let's say why air have 1.003 refractive index, and quartz glass 1.46?

what is it that makes materials strong ? density ? melted ? chemistry reactions ? strong nuclear force ? all of that ? regards garfield1729

Knowing the portion of the link BD has a uniform cross-sectional area of 800mm^2, determine the magnitude of the load P for which the normal stress in that portion of BD is 50 Mpa. (Hint draw a free body diagram of the link ABC) http://img137.imageshack.us/img137/9845/problmezf4.png sorry for...

I heard that in materials science you don't get to use that much math and physics, but mostly chemistry, is that true? If not, what kind of physics do grads in material science have to learn? And how is it combining material science with mechanical engineering?, is this a good idea?