Materials Definition and 919 Threads

Homework Statement We all know the egg drop, and I am stuck as to what to do with the extreme little amount of materials we are allowed to use. Here they are: 1 regular supermarket egg 5 sheets of printer paper 1m of scotch tape We are to drop it once from the ceiling of our...

Hi all, 1. The problem statement A copper specimen, initially at 293K, is immersed in a bath of liquid salt at 773K. The bath is agitated and the heat transfer at the surface of the metal is effectively perfect. A temperature of 723K is measured at 5mm below the surface of the metal item...

You have a flat wooden surface, some rope, some nails and a pencil - how do you draw parabola using just that?

As grotesque as the title may appear to suggest, I basically want to understand just that. Why is it that EM radiation of each group of wavelengths (visible, IR, UV etc.) manages to penetrate materials with varying ease. From what I've seen so far - and I haven't studied this directly, I'm just...

Hello all, I am new on this, I am making a simulation of a microbattery which use Ni(OH)2, Nickel(II) Hydorxide, as the cathode. I am having problems to find the information about the diffusion coeficient and the electrical conductivity of Ni(OH)2. I try in the CRC Handbook of...

if I have 3 materials and mixed it, can I compute for the specific heat of the "mixed" material? i have the data of the specific heat of each of the material and the precentage by weight. example: material 1 is 46% of the total weight, material 2 is 52% and material 3 is 2% cd =...

Hello all, My background is in physics, and I'm entering a graduate program for materials science and engineering this fall. I was wondering if anyone had any generic or specific advice before starting. Thank you.

Homework Statement A crane consists of a crane arm which is held in place and moved by strong steel cables. The crane arm is a truss structure, which is a rigid framework of quite thin steel beams welded together, forming many triangles. The cables are made of steel and they are not one...

Building Materials Refractive Index?? Hi all, does anybody know the refractive indices of these materials (used in houses)? - Wall bricks - Wood (used in doors) - Glass - Plastic - Concrete (in ceiling and floor) and any other common materials :) thanks in advance

So, i was thinking about this and figured out this: depending on electron orbit and, corespondingly, speed around the nuclei and energy of the photon, if the electron makes full cycle by the time it re-emits that photon the material is reflective - electron is in the same position where it...

I'm unsure how to approach this, as solid blocks of materials next to each other (e.g. steel and air) with no barrier inbetween as shown on http://en.wikipedia.org/wiki/Thermal_conductivity "x" would equal zero, this can't be correct. Is there another equation relating temperature difference...

Homework Statement Use calculations to determine what could happen to the 215mm wide glass window if it is tightly fitted into teh aluminum frame. The temperature in the mechanical wrokshop was 20 C The Maximum temperature in Bahrain = 55 C THe Minimum temperature in Bahrain = 5 C...

Hi Guys, I wanted to do an experiment testing the photoelectric effect but am having trouble getting light with energy higher than ~4 eV(300nm) through my window into vacuum as it's made of BK7 instead of something like fused silica. Does anyone know of a good material to use with a work...

A common thought after one learns about the limit of the speed of light is that a long rod when pushed would seem to cause the other end to move instantly, thus carrying information faster than light. The reason this isn't the case is because the movement will only travel through the rod at the...

Hello! In my geometry class we are going to be making a bridge. The materials are: 15 3mm x 3mm x 683mm balsa wood glue cutters Arch bridges are to difficult for our materials and we can't make a suspension bridge because we have no string. What is the strongest bridge I can make...

Homework Statement Hi everyone. I am attempting to calculate the internal moment at point B about the y-axis. I have correctly found everything else. My calculations: Weight of 500mm section of pipe = 58.9N Weight of 400mm section of pipe = 47.1N Vertical reaction at A = 58.9 + 47.1 = 106N...

Homework Statement A steel tube with a 32mm outer diameter and a 4mm thickness is placed in a vice and is adjusted so that the jaws tough the ends of the tube without exerting any pressure on them. The two forces shown are then applied to the tube. After these forces are applied, the vice is...

The title should give a rough overview of my question. I am going to a liberal arts college (Wesleyan university) and shall take the 3/2 engineering program, which means a double major in physics and some kind of engineering AFTER 3 years and getting my BA in physics. So I should be getting...

Does anybody know the acoustic properties of carbon fiber. I've used google extensively but I've had no success. Is there a well known reference book within the materials engineering realm that gives the sound absorption coefficient (also known as the Noise Reduction Coefficient (NRC)) of varius...

Homework Statement hey guys, I've got an assignment and its asking me to explain why some materials to have the same toughness value, but quite differnt fracture toughness values? i really don't understand wats the difference between toughness and fracture toughness? any help would be...

Just want to know what happen to a material when placed in a magnetic field? and does anything happen the magnetic field

I'm wondering about general magnetic forces, specifically the behavior of unmagnetized ferromagnetic materials in a magnetic field. I.e., a simple bar or electromagnet picking up an unmagnetized piece of iron. Are there formulas to explain this behavior? The lorenz force equations by...

Homework Statement A rigid steel plate is supported by three posts of high-strength concrete each having an effective cross-sectional area A =40000 mm2 and length L = 2 m. Before the load P is applied, the middle post is shorter than the others by an amount s = 1.0 mm. Determine the...

What could you do to obtain a more precise measure of the elastic modulus of a material in tensile testing?

I have Mechanics of Materials By James M Gere the 5th edition. My class uses the 7th edition which has been virtully the same so far. I have to do section 9.2 problems 1,2,3,4 for homework from the 7th edition. In the 5th problems for chapter 9 start on section 9.3. So i was wondering if anyone...

Homework Statement Shaft AB is fixed at point A and is subjected to a torque T = 2.5 kN·m applied at point B and an axial force P = 30 kN applied at point C. The actual shaft specifications (type of material, prismatic / changing cross sections are left up to us and is NOT the point of...

I am doing a Mini-Project on the solar impulse aircraft. http://www.solarimpulse.com/index.php You may or may not have heard about if before, but guess you would have. --- Aim of the project is to suggest ways to improve the project under several catagories - Propulation -...

Can someone list any physics textbooks or any other sort of learning material that i can use. It should cover most of classical mechanics (including electrodynamics, thermodynamics, etc,,,). I prefer it to have a lot of math, better than none. Also, are there separate books for quantum mechanics...

Homework Statement C1 = 12uF, C2=20uF, and the capacitors are charged so that the voltage across each capacitor is 6V. When a dielectric material is inserted between the plates of C1, the charge on C2 changes by 32 uC. Calculate the dielectric constant of the material, k. (PS. C1 is parallel...

Homework Statement Homework Equations tao=Tc/J theta=TL/JG The Attempt at a Solution I got the torque of the motor as 210,085lb-in Then I converted the 4* to .698 rad From there I plugged it into the equations. I solved for T from tao=Tc/J then plugged that T into the...

This question may belong under the chemistry section, but here goes. Does anyone know of a resource that identifies the origin of all the material objects you see around you every day? For example, that glass you are holding was origionally silicon oxide, otherwise know as sand.

Hi all ,it is my first post so sorry if I make any mistake ,we all know about the total internal reflection in which when we passed light in any material with an angle greater than the critical angle then it will bound or catch inside the light, Now I want to prepare a list of the such...

If I touch a variety of materials all at the same low temperature, such as wood, metal, bronze, plastic - the most conductive will clearly feel the coldest (even as they're all at the same temp) because those materials are able to transfer heat and conduct with less thermal or electrical...

Homework Statement A long retaining wall is braced by wood shores set at an angle of 30 degrees and supported by concrete thrust blocks. The shores are evenly spaced, 3m apart. For analysis purposes, the wall and shored are idealized. Note that the base of the wall and both ends of the...

How do lasers work? Are there comercially bought materials to make a laser? What is the minimum wattage for a steel cutting laser? And does anyone know some cool experiments to do with lasers? Thanks in advance.

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I'm studying about piezoelectric material. The electro - mechanical property of this material can be described by the following constitutive equation: Sij is the compliance matrix, and dmi is the piezoelectric constant for the materials The matrix form of the equation: Applying...

Dear all, I have some problems with a program called the simulation of laser interaction with materials. In this program, they asked for some parameters which I am unsure of but I believe it has something to do with mesh size for simulating the thermal conduction. This is a 1D heat conduction...

Hi, I'm currently in my final year doing an Materials Science and Eng. BSc at IPTME (Loughborough University, UK). Although I've been approched by some companies, I'm not entirely sure what line of work I'd be doing. If there are any materials engineers out there I'd be interested to know what...

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...

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...