Material Definition and 1000 Threads

Homework Statement A cylinder made out of AL 6061-T5, dimensions d 10mm, L 28mm. Is put into an oven pre-heated to 100 deg C. How long will it take for the cylinder to reach 100 deg C ? Homework Equations None given, this is not a homework question or even material I have been taught. I have...

I feel as though my ability to properly write up lab books when I do/after I do experiments is really weak. I struggle to analyse the data in a meaningful way. I don't know how to/when to calculate errors properly. I'm near useless when it comes to logarithmic graphs, or inferring any important...

I know that in a vacuum, speed of light is constant. My question is more about the speed of light in a material like air. Dispersion of light in a prism tells us that the speed of light or the material index depends on the wavelength ( or frequency which is constant ) so I thought that air...

I don't know if this is the right way of describing it, but I need to activate an area of capacitance on a touchscreen by applying some current to a piece of conducting material like tinfoil. I am needing to remotely turn pages on a touchscreen ereading device with a microcontroller, and this...

Hi all, I want to get some sort of polymer that is opaque to infrared (absorbs wavelengths above 700 nm very well) but transparent to visible light (does not absorb much light below 700 nm). Does this even exist without being a meta material?

which commercially available material has maximum strength but minimum weight ?

In stories regarding the "Roswell UFO crash", there are claims of alien metal foil that (depending on who you ask! :) ) you couldn't cut with a knife, couldn't tear it by hand, and which you could crumple up, and when released from your hand, it would unfold again to a nice, smooth sheet. Now...

Hi all, I am wondering how is it possible that the polarization effects of a dielectric material remain confined inside the material itself. That is: for a LIH dielectric, the equations state that the electric field inside the material is reduced by \epsilon_r. But outside the material, no...

Hello. I am thinking about creating an extremely lightweight running shoe to simulate barefoot running, and I need help on picking a material for the sole. 1. It has to be cheap 2.It has to be strong 3.No Metal 4.It has to be extremely bendable(able to role up into a tube)

hello! is there a material or substance that can be detected using some kind of waves (magnetic, electromagnetic, ultrasound, infrared, whatever, etc) with extreme specificity (ie. no other materials or substances are to be mistaken) with extreme sensitivity (ie. a nanometer of that material or...

Hello everyone! First time asking a question here, go easy on me! I am a first year Mech-Eng student in Ireland, and I need some guidance from one of the amazing brains here at physicsforums. I am told by my thermofluids lecturer that in thermal expansion, the amount of material expanding is...

I am helping one of my old physics professor and his Phd design a low-atmospheric vacuum chamber and we're looking at different materials to prevent outgassing. However the tank is almost 1m long and all the equipment inside must be taken out and checked after each test. It would be nice if we...

hi all, I'm creating a physics based game. My design works by pre-fracturing objects into distinctive chunks at authortime, to prevent extensive processing later (some realtime fracturing will also occur, but that's unrelated). So i have lots of walls that are made up of lots of little chunks...

Hi I have a the problems! i need this materials for dielectric : 1.pvc (Kg) 2.dop (Kg) 3.carbonate (kG) so, i Specify this propertise for dielectric : 1.T(Tensile strength) =16 2.E(elongation) =300 3.Density=1.45 4. H(Hardness)=78 now, I need to...

Hi I'm having an issue ANSOFT MAXWELL : Assigning a permanent magnetic material to a body (for ex NDFE35) provides me a means of setting the magnetization direction (through x,y,z unit vectors ) inside the material settings so if i have multiple PM bodies rotated :- 1- do i need to create a...

Hello all, I had clarified that refractive index of material such as(aluminium, copper, lead, teflon)changes with the temperature. the refractive index change even for this temperature range: -196 to 25°C ? I need to know like any law which gives a direct relationship between 1)the density and...

Hello guys, actually I'am working on a model to describe the creep-behaviour of a concrete specimen. This model is based on a 'generalized maxwell-chain'. I attached a picture, where you can see it: The acting load is the tension \sigma, while E_0 and E_1 are the stiffnesses of the...

I'm not sure if this would be the correct place to ask this, but I am planning on creating something that could very well increase some physical attributes of the human body. to do so I have to succeed in what I believe is the most complicated step in my experiment. so I need to know, is it...

What material has the lowest melting point? I'm doing an interesting research project of finding an invisible ink. My purpose is to find a material on which I can write on and has a very low melting point. I want to write on this kind of material by using my invisible ink. From my research...

http://physics.stackexchange.com/questions/156708/can-the-relative-permittivity-of-a-semiconductor-material-be-lower-than-1 To measure the relative permittivity of a p-type semiconductor material (a metal phthalocyanine ) , a M-S-M structure was made by thermal evaporation method. The...

1. Problem statement A steel rod supporting a stress of 8000 psi at 1000 ◦ F is not to exceed 5 % creep strain. Knowing that the steady-state creep rate can be expressed by an equation of the form ##\dot{\epsilon}_{s}^{C}=B|\sigma |^{n} exp \left(\frac{-Q}{kT} \right)## ε⋅, strain rate B...

I’m searching for an introduction to relativistic Boltzmann equation. (Sorry, I know this is a question about learning material) I’ve read an excellent script from David Tong about non-relativistic kinetic theory (from Liouville to Navier-Stokes using Boltzmann equation (see link below)...

I looked somewhat extensively through the threads to see if this question has been asked before, so if it has, I offer my sincerest apologies. I'm a second year community college student and only recently decided for certain that I will be majoring in a mathematical subject (Physics or Econ)...

There are conductors with loosely bound electrons such as Cu, what is a conductor that contains loosely bound "holes"?

Hi all, I have a general question about material properties. We know that the material property value depends on the input level. For example, the permittivity in a dielectric material changes depending on the applied electric field. That being said, when we apply an alternating electric...

I'm attempting to figure out the torque required for a twist drill bit to shear through a material. I have no idea if this is even remotely correct but this is the process I used. Ultimate shear strength = Force/Area Therefore Force = USS x Area The USS of the material = 360 N/mm^2 I...

Hi guys, Would like to know what's the highest compressive strength ever measured in any material, and what material that might be. Specifically wondering if there are any materials with gigapascal-level compressive strengths. Thanks! Rgds, Wally

I'm trying to make a blimp robot, I want to get into the drone-building hobby but right now a quadrotor is too expensive, plus I want to be a bit more original. I need something that I can make the balloon out of that won't leak (so I don't have to refill it often) and reasonably durable...

What's a suitable Material of construction for equipment handling hot brine (NaCl) solutions? Temperature is max approx. 100 C. I'm conflicted if or not SS316 works? I looked up an old handbook and it reported a corrosion rate of 0.2 mm/year (@80 C) which seems not too bad to me. But I've...

Homework Statement A very large slab of material of thickness d lies perpendicularly to a uniform magnetic field \vec H_0 = \vec a_zH_0, where \vec a_z is the unit vector in the z-direction. Determine the magnetic field intensity (ignoring edge effect) in the slab: a) if the slab material...

Homework Statement A coating of n1 = 1.33 material is to be added to n2 = 1.50 glass, in order to make it "irridescent." a) What is the thinnest layer of material which will have a reflection maximum for normal-incidence light at BOTH 400 and 600 nm (vacuum) wavelength? b) This thickness will...

I am working on a project, however I am having trouble finding the right material for it to work. I am looking for a nano-material or any molecule that will emit a radio frequency when subjected to a voltage or a current at around 37 degrees Celsius. I would really appreciate it if someone could...

Dear Friends, I am working on a project in which we need to shield an electrical field with a heavy 1 MHz component, at the same time, sparing the magnetic field as much as we can. With our limited knowledge, we came to the conclusion that a material with 10 kOhm conductivity would do this...

I need some informative books for a beginner. However, I find most beginner textbooks too simple, vague and incomprehensive. I find it annoying that many texts are extremely vocabulary based, and fail to inform the reader of HOW particular physics mechanisms work. Instead, these texts vaguely...

Dear all, I'm a university student in charge of developing a biochemical device (reactor) for the depuration of leather factory wastewaters, this is an european project leaded by Ambiental Engineering University of Florence. Part of this device should be colonized with fungi in order to purify...

Homework Statement A sphere of linear dielectric material with permittivity ##\epsilon_1## and radius ##a## is surrounded by an infinite region of linear permittivity ##\epsilon_2##. In the spherical region, there is free charge embedded given by ##\rho_{free}=\beta r^2##, ##0<r<a##, where...

I put helium in a balloon (with a maximum pressure of 1.5-1.7 atm), but I do not want changes in the volume, so I have to use a rigid material (non-elastic). To make sure that there is only helium in the balloon, I have to create a "strong vacuum." My fear 'that, in the material can break or...

Lay person here... If there was a new metal that was discovered with extremely high electrical conductivity and corrosion resistance but no thermal conductivity, what do you image its industrial uses might be?

Homework Statement You are considering two different designs for a walking cane. Both designs use hollow metal tubes, but design A has a circular cross section (outer diameter h) whereas design B has a square cross section (outer width and length h). Both canes are designed to withstand an end...

Hi to all of you, As the Biot-Savart-Law is based on experimentations in air, i like to know how to calculate the magnetic flux density in material with much greater permeability, where the circular like shape of the field distribution troughout the vicinity does not apply. Does anyone has a...

Would it be possible to use a 3D printer to print plastic (PLA for example) that could be smashed or warped by sound under 110dBs? I'm a biologist, trying to recreate what happens to hair cells in the inner ear when you damage them. Thanks.

Hi all, I'm looking for physical and mathematical explanations for a phenomenon I've noticed when working with rotated material properties relative to an XYZ coordinate system. For certain rotations (~40 to ~50 degrees) about a single axis the S12, S13, or S23 components of the compliance...

Homework Statement Using Darcy’s law, plus another appropriate relationship, derive a single equation for the pressure distribution in a porous material. Your equation should be stated in terms of generic operators (i.e. without assuming any specific coordinate system) and allow for the fact...

Homework Statement The cross section of a 20 cm thick, 3 m wide, and 1 m high composite wall is shown. The conductivities of materials A, B and C are 1.0, 0.1, and 0.05 W m-1 K-1, respectively. One side is exposed to air at 295 K with a heat transfer coefficient of 4 W m-2 K-1, and the other...

Homework Statement A body is moving, with the following data (these are all dependencies of the radius vector components respective to time): x(t)=At2, A>0; y(t)=Bt, B>0, z(t)=0. How does the trajectory of this movement look? Homework Equations r=x(t)i+y(t)j+z(t)k Velocity=dr/dt The Attempt at...

I have an issue with this question: An aqueous solution containing 15% NaOH and 0.5% NaCl is concentrated at a rate of 100 kg/min in an evaporator. The concentrated solution is then mixed with 2000 kg of aqueous NaOH solution in a mixer. At the end of one hour a sample is collected from the...

Hello, I'm trying to create the coldest freezer pack that is still soft and pliable. (Or will at least soften up within 10 minutes). It should also ideally stay cold for as long as possible. I've experimented with a few options so far and Water + Glycerin seems pretty good. If you add just a...

Hi, Sorry for double posting but I wasn't sure of the right thread. I am working with a colloidal system in which the particles are heavier than liquid. However when I add styrofoam to the system, the particles float. I can't seem to understand why the heavier particles float instead of...

Homework Statement Given that a rock is 60% porous, and if it's subjected to a large pressure that closes the pore spaces of the rock, what is the dilatation Homework Equations dilatation = ΔV/Vo= εxx + εyy + εzz The Attempt at a Solution Is this problem as easy as it states? If...

This is what we have in text-books and in Wikipedia: ρ=ρb+ρf and from there we get ∇.D=ρf. But I am unable to understand why we are not considering the bound surface charge in deriving this equation. Can anyone explain this to me.