Metal Definition and 999 Threads

Homework Statement Homework EquationsThe Attempt at a Solution The only thing that helped me was that with excess NaOH, the white precipitate dissolves. The only compounds I know that do this are zinc hydroxide and aluminium hydroxide. However, I don't know how the other reactions will help...

This snapshot is from the book Solid State Physics by Ashcroft,Mermin. They represented the Field and Momentum as the real part of a complex function. As far as what I understand, we represent fields in complex notations for our own convenience over the standard real representation which results...

For those who don't know there exists a sport called robot combat. Two robots enter an area and fight until one is unable to move anymore or its owner taps out. I have a novel idea for a weapon for a robot but I am unsure if the maths works out so that it will be practical. Suppose I take a...

I'm working on a solar heated pump project and require and suitable metal ..that'll absorb as well as radiate heat well. It should should also be cheap to use .

Homework Statement Charged metal sphere hanging on an isolated thread of negligible mass is put in a homogeneous horizontal electric field so that the thread makes a 45 degree angle with the el. field. What angle does the thread with the sphere close with the el. field after we remove 40% of...

Guys... If there is a bar, half of it is Copper and another half is Steel (Length wise) and both of its ends are at 1000K and I want to know how to find the temperature- length curve. this was an interview Question by the way.

I'm a design draftsman, I have bar of 17-4 stainless steel it weighs 6.9 lbs. The Product Data Sheet shows a specific heat 0.11 (BTU/lb/F (32-212F) (www.aksteel.com) It's at room temperature or 70 degrees F. I want to cool the bar to 50 degrees F. The surface area of the bar is 245 sq. inches...

I bought one of these plasma globes, decided to do some experiments with it. Since a fluorescent bulb will light up if It's put near the plasma ball, i tried the same with two HID lamps. The Metal Halide shows a very pale white arc, which disappears as soon as the plasma ball is turned off...

Consider we have an iron piece. If we could somehow tap on the iron with our finger for a very long long time, I mean millions of years, would it ever be able to make a dent?

Hi there, I have a question that I think has an answer but I cannot find it in the literature in any convincing way: I am using two models, WKB based and TMM based to calculate the transmission probability of electrons through a (initially rectangular) thin potential of the order of 1-2nm...

First of all i must say that i have lack of knowledge about physics. I have this silly idea to spray my metal roof in a humid area. No lack of groundwater and I am intending to sprinkle my metal roof with groundwater during solar peakhours. The roof is total only 30m2. I understand that...

For a flat layout sheet metal part, is the bend line located directly in the middle of the bend allowance section, or is it inset from one side by a distance of the bend radius? So for a U-channel with an opening of approx. 4.56" (distance between inside of legs), would the distance between the...

Hello! I'm having some trouble understanding stress and strain rations in sheet metal forming. I understand that they're constants, but how do you calculate them? Or are they usually given? Thank you!

Hello! Can someone please tell me where I'm messing up in this problem? At 4% and 8% elongation, the loads on a tensile test-piece of half-hard aluminium alloy are 1.59 kN and 1.66 kN respectively. The test-piece has an initial width of 10 mm, thickness of 1.4 mm and gauge length of 50 mm...

1. Homework Statement Why is there no electric field strength in a metal sphere? Is it because the sum of the individial electric field strength of the charges in the sphere is zero? How is that possible? Homework EquationsThe Attempt at a Solution

I know C=Epsilon0(A)/delta x From the problem, C=3,000 Epsilon0 = 8.85 × 10^-12 and delta x is .5mm The answer is supposed to be given in meters and should be close to 40,000 but I got 1.6*10^11m...help please!

I recently acquired a 39 gram sample of U-238 metal. I ran a gamma spectrum on the sample and found a major peak around 97 keV. I couldn't find any documents that mentioned this peak for U-238, but it is very prominent. I ran a gamma ray spectrum on a 5 gram Uranium Oxide sample and it also...

I have approximately 30 pounds of discarded phone wire. I would like to recycle the metals (copper?) within, but don't know if it is feasible or even worth attempting. I also just returned from helping a parent clean out the garage, including a retired aerospace engineer's vast collection of...

Hi. I read that one method of hardening a metal is through strengthening with a second phase. I'm not entirely sure I understand the phrase "strengthening with a second phase". Can the phrase "strengthening with a second phase" be shown on a phase diagram? Thanks. P.S. I seem to have...

https://www.yahoo.com/news/watch-metal-foam-dissolves-bullet-182400907.html These materials look really interesting. I'd like to learn more about them, anybody familiar with these materials?

Homework Statement An uncharged metal sphere hangs from a nylon thread. When a positively charged, nonconducting glass rod is brought close to the metal sphere, the sphere is drawn toward the rod. But if the sphere touches the rod, the sphere suddenly flies away from the rod. Explain why the...

Homework Statement A metal sphere of charge +6μC is surrounded by a metal shell of net charge +6μC. Which of the following diagrams represents the electric field lines of the system? Homework EquationsThe Attempt at a Solution The correct answer provided by my teacher is a figure with 12...

Homework Statement The specific heat capacity of a metal at low temperature (T) is given as ##C_p = 32\left({\dfrac{T}{400}}\right)^3## (kJK-1kg-1). A 100g vessel of this metal is to be cooled from 20 K to 4 K by a special refrigerator operating at room temperature (27°C). The amount of work...

I'm trying to understand the effect on a metal alloy of UV light (diode or laser) pulsing at about 1MHz. I am assuming that the stirring of atoms will generate heat, possibly moving the alloy to its eutectic point (depending on the alloy) and in particular to atomic motion. Can anyone...

I've been using the following equation for thermal resistance to make basic calculations for a few different engineering designs: $$R_t = \frac{L}{kA} $$ Where L is the resistance path length, A is the cross-sectional area perpendicular to this path and k is the thermal conductivity of the...

Hello All I could get some help I would greatly appreciate it. I am trying to figure how to calculate the dissolution time of sphere undergoing constant corrosion at a rate of corrosion. Through a little google-fu, I found an article which gives me the solution (...

Hi. If a metal is very pure but still has other elements in it like this: -1 or 2 at 500ppm, 1 at 150ppm, 2 or 3 at 20-30ppm, 1 or 2 at 3-5ppm. Which are manufacturing impurities and which are deliberate doping? Are the 500ppm doping?

Homework Statement Uncharged metal plate area S and thickness d located at a distance r from the point charge q and oriented perpendicular to the vector r, as shown below. Find the electric force between the plate and the charge. The plate thickness is less, and the distance r is much greater...

I am doing business with a Japanese partner to help japanese people to remain safe during earthquakes which require building a small metallic shelter in their homes, it should stand the destruction during an earthquake. My question, what metal is the right choice? :oldconfused: It must have...

Homework Statement I had a lab where we put 50 grams of a metal smaple into a little bowl and then heated it with steam from a big beaker thing. Anyway, my question is about the errors I got in this lab when finding the specific heat of the metal. I had some high percent errors for Aluminum...

Homework Statement This problem has two parts. A laser produces photons having an energy, E = 3.5eV. a) What is the wavelength of photons produced, assuming that the index of refraction is 1.6? ->221nm b) If this laser beam is focused on the clean surface of a metal having a work function of...

I'll preface this with saying I'm an Industrial Designer, not an engineer. I also build workshop furniture as a hobby, which this question is in reference to. I'm building a motorcycle lift table. I'm curious, is there a chart that compares things like tubing material, size, strength and...

Hi guys I was wondering of someone on here could briefly enlighten me on the chemical reactions that would occur with a Teflon Coated high carbon steel hook and a lead sinker while underwater? I am looking into the signals that may or may not be given off by these items both separately and with...

Hello. I need to nickel plate an item, but there are no sources of pure nickel in my immediate area other than guitar strings. I picked up a set, which was labeled as pure nickel, but it was obvious upon inspection that only the wound strings had nickel, and that was only the woven outer layer...

how come they all cannot be reduced by a reducing agent such as hydrogen or carbon, why is it that only some can, the only thing i came up with is that, only those metals that are listed under the activity series can.

Homework Statement At what rate does a 0.1m cube of metal with emissivity e=0.75 radiate energy if it is at a temperature of 200C? Homework Equations H=AeσT^4, σ=5.67 x10^-8 The Attempt at a Solution I found the area of the cute to be A=(0.1m)^2=0.01m, and the turned 200C into 473K, but when...

Dear members, Some days ago, I received the following exercise but I have never studied thermodynamics before and I don't know very well where to start, the exercise is about Heat Transfer and the Finite Difference Method and I must program the solution using Petsc and C++. About the Finite...

I am trying to model metal NPs capped with organic agents to simulate their phase transfer behavior from aqueous to organic. Not doing computational chemistry courses has had me to disadvantage. Would love some initiation or a jump start primer for the same. Looking forward for cues to get me...

A typical example is a iron chair gets cold in winters and wooden chain not. We all know iron is more conductive but how this thing possible at molecular level of conduction of heat from metal to air. In general conduction I know it is possible due to vibration transfer of molecules but how it's...

whenever any plate of system of parallel plates is earthed total charge on outer faces of the plates will become zero .Is it always true?or only in case of system of two plates?

I was just looking through a few different solutions in Griffiths EM and I must have not realized it, but do bound and free charges both contribute to the overall electric field? For example: when dealing with a capacitor with a dielectric between it, one of the solutions wants to find the...

Can a large body of electrolyte be used for ground? For example, if we placed an insulated metal into the ocean. If it was charged, would the ocean water be treated as the other electrode in calculating it's capacitance?

I am thinking about using a metal mask for BOE or HF etching because I realize that for normal photoresist, it will gradually peel off and affect my results. I don't know which metal is the best--so far, I see people use Cr/Au, Al, and Ni. Anybody knows which metal will give the best result?

Hi all, first post here. I'm currently faced with an assignment in a class where we really haven't been taught anything and have to figure it out on our own. We've been asked to design an industrial lift system to raise approximately 3000 kg up 25 stories. I have done a lot of research and...

When blaster or laser is used to make a hole in a piece of metal is any of the matter of the metal completely eliminated from the universe?

If there is a small object with positive charge placed above a metal plate, the object induces a negative charge on the surface of the plate facing the object. Let's call this surface as S1. (The metal plate is initially uncharged). But from conservation of charge, the net charge in a metal...

Homework Statement Problem 18B.13 from Transport Phenomena, BSL. Tarnishing of metal surfaces. In the oxidation of most metals the volume of oxide produced is greater than that of the metal consumed. This oxide thus tends to form a compact film, effectively insulating the oxygen and metal from...

Homework Statement Zinc metal is added to hydrochloric acid to generate hydrogen gas and is collected over a liquid whose vapor pressure is the same as that of pure water at 20.0°C (18 torr). The volume of the mixture is 1.7 L, and its total pressure is 0.987 atm. Determine the number of moles...

Homework Statement Two small bar magnets X and Y are released from rest at the same height above the ground. X falls directly to the ground, but Y passes through a metal right which is fixed with its plane horizontal. Does X reach the ground: (A) at the same time as Y, (B) before Y, (C) after...

Homework Statement An otherwise free metal rod of length L = 67-cm is clamped at a point L/18 from one end. A standing wave is set up on the rod. What is its longest possible wavelength? The Attempt at a Solution where do I go wrong? thanks