Metal Definition and 999 Threads

Homework Statement Estimate the resistivity of an amorphous metal whose mean free path is of the order of an atomic spacing. Compare your answer to crystalline copper.Homework Equations VF = h(bar) KF / m VF = l / τ ρ = m / n e2 τ The Attempt at a Solution I think my real issue with this...

If there is a parallel plate capacitor with plate area, A, plate separation, d, and a slab of copper of thickness, b, is inserted exactly halfway between the plates. How to find it's new capacitance, C', and new potential difference, V' ? Answer: V' = E(d-b) and C' = εA / (d-b) I...

Hello guys I am working on designing somethings and I am using metal tubing. I do not know what type of metal tubing I am going to use this all depends on the math after I work my problem out. I am not sure what formulas to look up or what strength test I need to look up. For example if I have...

I want to make a unibody, durable version of the above that won't chaffe skin and survives/resists getting distorted even if you try to twist the metal hook loop. Basically I have the above device. I pulled an twisted on the hook and the hook ripped out. I'm looking to create perhaps a metal or...

Homework Statement Two large, flat metal plates are separated by a distance that is very small compared to their height and width. The conductors are given equal but opposite uniform surface charge densities +σ and -σ. Ignore edge effects and use Gauss's law to show a) the electric field...

I am trying to use a metal film resistor to limit the current inside a dilution fridge (to reduce noise power from it), but I couldn't confirm if the metal film resistor is going to survive (or it goes superconducting) at ~3 Kelvin, searching a bit on the web but still I couldn't find the...

Hello, I wonder whether I can replace the Metal gears and other parts with Plastic material? If so, what kind of plastic material should I use? There is no heat and the force is also not that great but the speed is. This is not for toy but industrial machinery, with gear diameter of about 10...

Hey guys. I am currently building a plan for a new metal sculpture of an alien reptile thing. The twist for me is that I want it's scales to be rotatable from being flat up to a 45 degree angle. The pivot needed would have to be fairly small ( scales are nearly inch wide) . I could not find...

What would happen to a metal superconductors taken below zero to a negative temperature? Would it loose its superconductivity?Regards, JDM

Hello, For the past 2 days I've been looking for a resource discussing the metal insulator transition using percolation theory. (The next part treats the Anderson and Mott models) I'm studying for a course of solid state physics where this is mentioned/summarized. The problem is that the...

Dear Friends, Merry Christmas to All. I am pleased to join this forum of Physics Experts. Please advise what is difference between tensile Strength and Bending Stress of Metal Sheets (Generally below 3.00mm and lighter). I very often encounter with cracking of steel sheets while bending in...

Given a material sample, what are the different experiments that one can perform on it to check if it's a conductor or a semiconductor. For eg, we can measure R at different temperatures. Anything else we can do?

Hi i want to know how to make a 3D metal box whose length, width, and height i can change. For example, i have a box of 3 m x 3 m x 3 m. i should be able to extend any dimension by a maximum of 1 meter i.e 4 meter (say). I want to use this to store items whose size is unknown, but the limits of...

What happens if a metal is heated and cooled at the same point at the same time?? will it expand or contract??

Hi everyone, I have been trying to find an equation to measure the length of a coil. The coil is a metal sheet that wraps around the loops as it creates. It looks like a roll of tape. I have been using two different formula, but it is not giving me the right results. 1. L = 0.065449 (OD^2 -...

Homework Statement A copper vessel of 100 gr contains water, 150 gr, and 8 gr of ice. a 100 gr piece of lead at 2000C is thrown in. what's the final temp' Homework Equations Specific heat copper: 0.093 Specific heat lead: 0.031 Melting heat water: 79.7[cal/gr] The Attempt at a Solution On the...

Homework Statement If the coefficient of static friction between the sighn and his hands is 0.6, and the coefficient of static friction between the sign and the wall is also 0.6, with what force must the boy push to keep the sign in place? Homework Equations 0.6(Fn)=100 N Fn=166.7 N The...

Here is a video of a funny accident that happened at a steel mill in Russia. Thousands of pounds of molten metal come pouring out of it's ladle onto the floor due to equipment failure. Fortunately no one was hurt in this incident, but the whole plant could have gone up in flames if the outcome...

Homework Statement in my book , i was told that for the emission of electron from a metal surface to occur , the photon which incident on the metal must have at least the energy more than the work function of metal , whereas for the emission of electron from H atom, the photon must have exactly...

Homework Statement when target metal is changed to heavier metal in X-ray tube, the min wavelength will not change. but the wavelength of the characteristics line will become smaller. my textbook gives me the above statement explaining much. can someone please explain it? thanks ! Homework...

Hi, I am trying to cut a parabolic curve in a piece of sheet metal using a numerically-controlled cutting machine (basically a very hard rotating router blade). The router blade is 10mm diameter. I want to achieve a parabolic cut in the sheet metal that adheres to the formula y=x^2 The...

Homework Statement Of the people passing through an airport metal detector, 0.5% activate it; Let X denote the number among a randomly selected group of 500 who activate it. 1) What is the PMF of X i) Using th CLT (approximate PMF) ii) Using the exact distribution of X 2) P(X = 5)...

Homework Statement One end of an insulated metal rod is maintained at 100∘C and the other end is maintained at 0.00 ∘C by an ice–water mixture. The rod has a length of 60.0cm and a cross-sectional area of 1.40cm2 . The heat conducted by the rod melts a mass of 7.15g of ice in a time of 15.0min...

Hi All I hope that someone where can help me out. Let's assume that we take a piece of Al foil and a Pt wire and put them into an ionic solution. We then apply a voltage difference of 2 V between the two. Al(+) and Pt(-). After a few seconds the Al electrode starts to corrode. Nothing new...

Homework Statement A metal sphere of radius ##R## carries a total charge ##Q##. What is the force of repulsion between the "northern" hemisphere and the "southern" hemisphere?Homework Equations The force per unit area on the surface of a conductor: \vec{f} = \frac{1}{2\epsilon_0}\sigma^2\hat{n}...

Hi guys! I have a question regarding liquid metals. Suppose you had a droplet of liquid metal in empty space. Take the droplet and connect it to a DC source. What happens if the voltage of the DC source exceeds the surface tension of the liquid metal droplet? Would the droplet split in two...

they are permanently stuck?

1. Insert a bar of copper of m(gram) into (HCl + H2O). After a while, its weight become m_1 (gram) which is smaller than m. Explain why and give a general formula to find m_1 2. None 3. I keep thinking how that becomes possible, because I learn that Cu can't react with HCl+H2O

Homework Statement (a) The metallic rectangular loop of length b and width a (ABCD) is mounted in an assembly, which allows it to be rotated about an axis bisecting AD and BC. The plane of the loop makes an angle θ to the horizontal and a uniform magnetic field B is applied vertically...

Hi, I am trying to solve the chemical equilibria in a kraft mill bleach plant to predict mineral scale deposits. I am using the van't Hoff equation to account for temperature dependence of the formation constants, but I need the enthalpy of reaction for all equilibria and I am missing some...

Homework Statement A girl pushes on a large stone sphere. The sphere has a mass of 8200 kg and a radius of 90 cm and floats with nearly zero friction on a thin layer of pressurized water. Suppose that she pushes on the sphere tangent to its surface with a steady force of F = 45N and that the...

Hi, I would like to calculate the force between a finite coil and a nearby metal plate. A pulsed current is supposed to flow into the magnetic coil, which will generate a magnetic field near the coil. Due to this magnetic field, an Eddy current will be produced in a nearby metal plate and...

I uploaded a photo to help explain the question, basically the blue rod is a -ve charged rod ( high voltage) gray one is metal and the brown is also metal but it's grounded , if gap A and B are filled with air , the high voltage will break down the air in both gaps and make 2 sparks in both gaps...

In terms of structure

Hi all, I have an idea for a project whereby I there would be an electromagnet pulling on a metal weight through wood. So: Electromagnet -> Wood -> Metal The basic idea is to stick things to wood with electromagnets. Can anyone recommend a material that could be bonded to the Metal what...

Homework Statement A colorless solution is known to contain one of these ions. Which ion is present if adding dilute HCl produces a white precipitate that dissolves when the solution is warmed? A) Ag+ B) Cu2+ C) Hg22+ D) Pb2+ Homework Equations N/A The Attempt at a Solution The...

I just wanted to clear one thing... in metals what type of potential the electrons are subjected to..?? Is it constant , sinusoidal , square or non-periodic..?? pleasez explain a bit in accordance with free electron theory.>!

Hello this is my first post in this forum. I would like to ask something relatively simple and I need a simple answer please, since I am not a physics expert. Does a metal that has been red-hot heated using a flame, emit electrons? (like the electrically heated cathode of a vacuum tube does)

Homework Statement Two metal rods, one silver and the other copper, are both immersed at one end in a steam chamber at a temperature of 100°C. The other end of each one is in an ice water bath at 0°C. The rods are 5.0 cm long and have a square cross-section that is 2.0 cm on a side. No heat is...

Hi all, this question may sound incredibly obvious to a degree of trolling, but I was having difficulty finding an online source that dealt with this subject. When one connects a metallic plate to, say, a positive end of a voltage source, is the metal actually oxidizing and changing to +1...

Homework Statement A sealed metal can is placed in a uniform external electric field of 10 N/C . The field points along the +x direction. The can is 20cm in length and 10cm in diameter. What's the value of the electric field at the center of the can? Homework Equations The Attempt at...

Hi. So let's say you have two identical cubes with expansion coefficients of approx. zero. These cubes are thermally in contact with each other, and otherwise isolated from the surroundings. One cube has a higher temperature than the other, so heat will flow from the hotter cube and to the...

Homework Statement Can't seem to upload the figure in my workbook so I'll describe it. A metal bar is placed on 2 rails that slope up with a gradually increasing tangent. The bar has a higher conductivity than the rest of the apparatus. The 2 ends of the rails at the bottom are connected to a...

If you have a knife edge (dual sided at 45°, 1/8" thick, and you want as little deformation as possible under a 50 lb. load, what would be the ideal alloy? Harden steel? Tungsten? High carbon steel? Application: two point guitar tremolo, total tension being around 100 lbs. Looking...

Hello, Are the electrons at the fermi level regarded as the "free electrons" of the metal? Also, how does one go about calculating the Fermi level? Is there an equation or is it experimentally determined? *Bonus question* Electrons that undergo phonon exchange and pair up are called...

In a solution of aqua regia (or other acids), if there is a precious metal dissolved, along with other metal ( such as other precious metals or base metals), and you add a powdered metal, you precipitate all the metals lower than it on the reactivity list. If however, you use a chemical...

Homework Statement Why is there such a large difference between the elastic moduli of metals and polymers? Homework Equations The Attempt at a Solution I am thinking because of the different bonding between metals and polymers. Since metals have metallic bonding and polymers...

As the title says, what is the electric potential of a metal cylinder? If I am missing any variables, which variables do I need? My little brother asked me this but I don't want to turn up short-handed. I'm not really a physics guy

Homework Statement An infinitely long thin metal strip of width w=12cm carries a current of I=10A that is uniformly distributed across its cross section. What is the magnetic field at point P a distance a=3cm above the center of the strip? Homework Equations dB = (μ0*dI)/(2*∏*r) The...

Hello Everyone, This is my first post. Background: I am an audio guy and seek to understand how cables contribute to the sound of my stereo. Issue: Do audio cables such as power cords, interconnects, and speaker cables "break in" as they are used? Typically, with high-end cables, users...