Materials Definition and 919 Threads

Hello everybody! I have an question, that seems silly, but i really need know that. When a material is subject to waves, he starts to oscillate in the frequency of the wave and this material becomes a source of secondary waves, this justifies including the reflection process of the waves...

Hello Everyone I have a mechanics of materials questions which I have been stuck on for hours, I just can't figure it out. Attached is the questions. I know the formula for deflection which is PL/ AE but what do i do with that formula in this situation? Any help would be...

Can anyone help me understand why magnetic flux flows through ferromagnetic materials like an iron ring? Also, say you have a toroid with a wire wrapped around it (in air) how can you say that the flux that goes through one "loop" will go through ALL the others? These are just some things...

Is it correct to say that all materials exhibit some form of magnetism? I was reading on Wikipedia that there are different kinds of magnetism (Ferromagnetic, ferrimagnetic, Paramagnetic, Diamagnetic) and that all materials exhibit at least one of them.

A cable has an unstretched length of 12.0m and is stretched by 1.2 x 10^(-4)m when a 6.4 x 10^(8) Pa stress is applied. What is the strain per unit volume in the cable in J m^(-3), when this stress is applied? Any help would be very nice. I don't understand what to do.

"interactions between polar materials and electric field" sorry typing error.polar materials are those who have a permanent dipole ( like water molecules ) but these dipoles doesn't appear on the macroscopic scale due to their random orientation , so what if this polar medium is subjected to...

Homework Statement Calculate the fraction of lattice sites that are Schottky defects for cesium chloride at its melting temperature (645C). Assume an energy for defect formation of 1.86eV. Homework Equations Number of lattice sites per cubic meter (N)...

What comes after materials engineering PhD? Somebody I know has recently started a PhD in materials engineering in a decent (top 20) engineering school. He is mostly passionate about his work and is focusing on ceramics research. Recently he has started sharing with me his fears about not being...

If the change in temperature is negative: 1st of all, is it possible? and second, if it's a bar between two rigid supports, does the reaction would have to be in tension instead of compression to compensate for the bars trying to contract due to temperature? Also what if it has an axial force...

I am to design a shock absorber for my project. Pl tell me what material the various components would be made of. Just gimme any rough idea you would have or just make a wild guess Anything! I just need a start and then I will take it from there. I have designed the thing on Solidworks but do...

ive been looking for materials relating to ultraconductors and have reached a dead end. can anyone give me a good link.

I've got homework assignment for 6 hours later but I could not even start to solve the problems below. I've done lots of research but I could not understand which equation must be used for each question.1. Compare the thermal velocity with the drift velocity of electrons in a divalent metal...

I'm going absolutely nuts over this chapter...ther seem to be millions of terms,which all seem to mean the same thing...could someone help me out?? Okay,the first set of questions I would like to get cleared is... 1. The proportional limit on a stress-strain curve is supposed to be the point...

I am currently doing a material characterisation project and have performed a standard tensile test on a number of 304 stainless steel specimens. I have obtained a number of stress-strain curves from the testing and have been told I need to relate them to the Ramberg-Osgood material model in...

I am currently doing a material characterisation project and have performed a standard tensile test on a number of 304 stainless steel specimens. I have obtained a number of stress-strain curves from the testing and have been told I need to relate them to the Ramberg-Osgood material model in...

In neutron activations, target materials are being beamed by high energy flux, thus making the target materials excited and undergo radioactive decay. Neutron analysis then can be performed after the materials are "cool" enough by placing inside the hood with enough shielding. My question is...

I'm trying to make something weird for a side project and I need some information from a physics person...what material, be it glass, plastic, some sort of alloy, etc... would conduct heat best in a microwave? Remember metal is not an option.

Homework Statement List the ductility, yield strength and Young's Modulus of steel, rubber, nylon, concrete, alluminum, glass and rubber Homework Equations none The Attempt at a Solution I tried google and wikipedia with not much luck so I figured i would ask here. Any repository...

Homework Statement The length of a 2mm diameter steel wire CD has been adjusted so that with no load applied a gap of 1.5mm exists between end B of the rigid beam ACB and a contact point E. Knowing E = 200GPa, determine where the 20kg block should be placed on the beam in order to cause...

Hi I need a companion text for my intro Mechanics of Materials book by Beers. I am somewhat frustrated in the inconsistency in explanation it will review a statics topic in excruciating detail then gloss over an important detail. I feel with another book in hand I should be able to conquer...

Homework Statement Conceptual question - When considering beam connected to something say a wall by a cylindar shaped pin, why is it when the beam is in tension near the pin the stress is high as the load is applied over a smaller cross section (normal cross section - profile of the pin) but...

Which book would you recommend for Strenght of Materials for mechanincal engineering student. Please don't tell me book on the basis of problem sets. I have my book which contains numerous problems but I want a book which explains the concept form very basic to deep. BTW how is the book by...

Here are some great Strenght Of Materials problems.. Scroll down and under the coursework problem click the example and take a look at the different problems.. Those are fully solved. I'm not sure how long the site will be active but its very helpful so download the pdf file before my professor...

in general, do ductile matreials fail due to shear or tensile stress i think that my lecturer said that brittle materials (such as concrete) will fail due to a low maximum shearing stress therefore breaking at 45 degrees in axial loading, and ductile materials have low tensile stress leaving...

when given a non homogeneous cross section, i know that i can find the bending(normal ) stresses by transforming the cross section into a homogeneous one by multiplying the area of one of the materials be 'n', where n=E1/E2, then i solve normally, finding the centroid of the new cross...

I know already that hot objects radiate infrared radiation, just to be clear. My question is, do all individual wavelengths of electromagnetic radiation heat objects that absorb that wavelength? Even if it heats it just barely, for the smallest fraction of a second.

"New Materials"(new china industry),could this be the next bill gates($$$) industry? thoughts?

Hello, I`m studying 1st year physics and I would really like to improve my basic maths. The thing is I don`t want to sit and first make up a random expression and then calculate the derivative, I would like to be able to print out hundreds and hundreds of small expressions with varying...

Hello all, While searching for a holiday gift for a younger sibling (who is rapidly becoming interested in the sciences), I remembered a demonstration from a high school physics course that sparked my own interest in physics. It involved a unique object - a light bulb with a needle and 4 black...

Hi all, it is interesting to compare materials scientist and physicist.. what you guys think of them..like essential qualities and abilities in researching in their fields. How do materials scientist and physicist shine in their work..which is interesting and challenging.. i hope i will get...

I am investigating the Young's Modulus of certain materials and what factors have an effect on the Young's Modulus of materials. I am going to be altering the temperature, my hypothesis being that increasing the temperature will lower the E of the materials. Are there other factors I could...

Just a quick question about mousetrap cars... Does anyone have suggestions about possible materials for mousetrap cars? NOT designs, but recommendations for materials to use on certain parts of the car. Thanks in advance.

how do i go about solving this im not sure I've learned this material yet but i have learned defrmations and deflections, i need to somehow find the force applied to the bars due to their exopansion and the restraint. what is \alpha exactly? the increase in length for each degree F??

I am in the process of applying to PhD programs in Materials Science, and I am having trouble deciding how to round-out my selection of graduate schools. I have been working very hard this semester to prepare graduate application materials and investigate programs in which I would be...

Hi, I was just looking over the "course calendar" for a materials science/engineering program at the University of Toronto (http://www.artsandscience.utoronto.ca/ofr/calendar/prg_mse.htm ). I find it strange that there is only ONE required math course throughout all 4 years. I know that there is...

Here is a problem that has been bothering me for some time... What is the source of electromagnetic radiation (usuall red visible light) coming from materials (such as metals) that are hot enough. An example that has always stuck with me is a demonstration that I witnessed at a car show of...

Can anyone give me some insight into any materials/substances that might bond to calcium fluoride (CaF2)? Any help is appreciated, thanks.

I hve the following problem to solve, I was wondering if someone could give me some guidance as how to approach ths type of question. The principal stresses at a pint of a shaft subject to bending and torsion at 120MPa and -40MPa. Determine the bending moment and torque knowing the shaft...

Hi Im trying to help a friend of mine out with this problem he has in a solid mechanics class he is taking, but it has been awhile since I took that course so i was hoping you guys could help me help him :) Here is the problem he gave me. in that image p1 p2 and E1 E2 are the...

Hello all, I am a student in need of advice. I am a Physics and Applied Math senior at Humboldt State University in California, which I am confident will not open any doors. Over the next 3 months I will be applying for PhD programs in Materials Science, with the goal of obtaining a...

Homework Statement refer to attachment Homework Equations The Attempt at a Solution I am completely confused at where to start can someone get me going in the right direction here as to one of the answers.

Homework Statement Question 6. Germanium forms a substitutional solid solution with silicon. (a) Compute the number of germanium atoms per cubic centimetre for a Ge-Si alloy that contains 25 w/o Ge and 75 w/o Si. (b) If, instead, phosphorus is added to Si to dope the material n-type at a...

Hello,everybody! I'm a PhD candidate from xi'an jiaotong university,china. There is an urgent need to make a deep understanding about the microstructure evolution of nuclear fuel materials under irradiation. To make my research more close to the frontiers, your suggestions are welcomed. I've...

In his second Auckland lecture, Feynman said that light doesn't slow down in materials, it still goes at c in the vacuum between molecules. It just gets [and I don't remember exactly what he said but something like] it just gets waylaid when it passes near matter, or maybe he said it is...

I have three different parts: 1. An Aluminum Bronze Outer Ring 2. A Neoprene Ring 3. A Phenolic Composite Ring. The (2) fits into a recess in (1), (2's) purpose is to seal between (1) & (3). What I would like to do is create a calculator on excel that will calculate the force required...

What causes water and other similar transparent things to become transparent? Visible light can pass through transparent solid object like glass but can't pass through many opaque objects. What is the reason? Again when liquid water turns into ice it loses its transparency. I'll be very...

Hi, I am looking for some guidance w.r.t modelling real world phenomena using ODE/PDE/SDE type equations. Are there books which go into the issues of modelling real world phenomena with these sorts of equations? Thanks in advance, Excor.

Is anyone familiar with materials which possesses a high tensile strength, but also a low young's modulus (high compliance)? I'm interested in a material which can support large deflections, while offering minimal resistance to it. Also, I'm specifically not interested in non-linear materials...

When the current in solenoid is turned off a steel core stays magnetized. The tiny atomic magnets remain lined up, even when the external field is removed. Why is that so?

Hello I am a student working on at home project and I need help on choosing a compressible, soft material that works safely with wiring and electricity. The kind of material I need is something that is compressible and soft, sort of like a foam or gel heal pad that people put in their shoe. The...