Metal Definition and 999 Threads

Which metallic material will have a maintenance free shine when polished? I want to machine auto emblems so I'm looking for a material that does not go dull when expose to the elements. Thanks!

I'm familiar with lightning rods taking advantage of the mutual repulsion of charges to shoot off a corona discharge off the sharp end and start a thunder, but why doesn't corona discharge happen to all charged metals? What makes air such a good insulator, when it's just gases, relatively few...

Homework Statement A steel bar 10cm long is welded end-to-end to a copper bar 20cm long. Both bars are insulated perfectly along their sides. Each bar has a radius of 2.0cm. The free end of the steel bar is maintained at 100 degrees C and the free end of the copper bar is maintained at 0...

[SOLVED] negative rod to uncharged metal ball: Homework Statement If a negatively charged rod is held near an uncharged metal ball, the metal ball: 1. becomes positively charged. 2. becomes polar. 3. Effect cannot be determined. 4. becomes negatively charged. 5. is unaffected. The...

Homework Statement An infinite, thin, uniformly charged rod (charge density lamda) is situated parallel to a metal plate at a distance d above it. Calculate the E-field close to the surface of the plane as a function of perpendicular distance to the rod. The Attempt at a Solution I...

hey guys i was wondering if anyone could help me with this question, kinda got stuck Homework Statement Figure 24-31 shows a section of a long, thin-walled metal tube of radius R = 5.56 cm, with a charge per unit length λ = 7.34 x 10-8 C/m. What is the magnitude E of the electric field at...

[SOLVED] Thermal Expansion Problem Homework Statement A metal ball is just able to pass through a metal ring. When the ball is heated thermal expansion will not allow it to pass through the ring. What would happen if the ring rather than the ball, were heated? Would the ball pass through...

hello! i am quite new to material engineering and so my question might seem a bit too obvious. her it is: i have a metal ring-(picture1(304 stainless steel)) i need to know what property of the metal defines the ring's resistance to "opening"- like shown in the second picture thank you very...

Hello! I am a grad student and am trying to acquire some Aluminum Metal Matrix composites with Boron Carbide reinforcement (15-20%) for research. I need the material to be in 1/4" thick sheets. Does anyone know of any companies that sell this sort of material? Thanks!

A piece of metal with a mass of 1.50 kilograms, specific heat of 200 J/kg · C°, and initial temperature of 100° C is dropped into an insulated jar that contains liquid with a mass of 3.00 kilograms, specific heat of l,000 J/kg · C°, and initial temperature of 0° C. The piece of metal is removed...

Dear Sir, This is Thangamani, doing research on sensor design. I have gone through Mr. Robert Dean (RF CMOS Designer, MEMS Optical, Inc) article that available on internet ( if not mistaken its from MEMS forum) discussed analytical solution about rectangular membrane. Since i am...

force exerted on walls of metal box...please help! 1. Homework Statement A cubic metal box that has 20-cm-long edges contains air at a pressure of 1.0 atm and a temperature of 300 K. The box is sealed so that the enclosed volume remains constant, and it is heated to a temperature of 400 K...

dear all can anyone tell me.. if i have a transmission line passed above a metalic surface, there will be a parasitic capacitance between the line and the surface. and it induces interference how can i measure it. and if there is any refrenece about the allowable induce voltage...

Homework Statement A thin, rectangular sheet of metal has a mass M and sides of length a and b. Use the parallel-axis theorem to calculate the moment of inertia of the sheet for an axis that is perpendicular to the plane of the sheet that passes through one corner of the sheet Homework...

Homework Statement Two 10-cm-diameter metal plates are 1.0 cm apart. They are charged to +/-12.5 nC. They are suddenly connected together by a 0.224-mm-diameter copper wire stretched taut from the center of one plate to the center of the other. A)What is the maximum current in the wire...

Homework Statement * A 14.0kg block of metal measuring 12cm x 10cm x 10cm is suspended from a scale and immersed in water. The 12.0 cm dimension is vertical and the top of the block is 5.05 cm below the surface of the water. (a) What are the forces acting on the top and on the bottom of...

A square metal plate 0.180 meters on each side is pivoted about an axis through point O at its center and perpendicular to the plate. Calculate the net torque about this axis due to the three forces shown in the figure if the magnitudes of the forces are F1 = 18.0 N F2 = 27.0 N and F3 = 14.0...

Homework Statement A metal container, which has a mass of 8.0 kg contains 14.3 kg of water. A 2.9-kg piece of the same metal, initially at a temperature of 190.0°C, is dropped into the water. The container and the water initially have a temperature of 15.1°C and the final temperature of the...

Hi, I carried out a couple of experiments with unknown group 2 salts; X and Y I added dilute NaOH to each of the salts which were now mixed with 1cm^3 of water; Y formed a precipitate (initially the solution was colourless as the solute had dissolved) whilst X turned colourless (X's...

Homework Statement If I have the horizontal range and a launch angle, how can I calculate the initial velocity of a metal ball if the vertical displacement is not zero? Homework Equations The Attempt at a Solution

My teacher marked my answers to this assignment as wrong. He wouldn't explain why, so I hope you guys will be kind enough to point me in the right way :smile: The reading of the sensitive ammeter was found to be 0.002mA. Radon-220 isotopes are introduced through the valve and it releases...

Are there any green, blue, or purple metal compounds (non-alloys)? Also, is there any list of all known stable metal compounds and their colors?

Homework Statement differance between tensile and yield strength. please help. Homework Equations The Attempt at a Solution

Homework Statement (Q) Calculate the center of mass of a semi-circular metal plate of uniform density ρ and thickness t. Let the radius of the plate be a. The mass of the plate is thus 1/2 (ρπat2). In your co-ordinate system, you must consider the x-axis passing through the bottom of the...

Rotational Equilibrium - Help! Homework Statement http://photos-a.ak.facebook.com/photos-ak-sf2p/v142/24/75/1238100168/n1238100168_30095452_8017.jpg A uniform metal bar of mass 100 kg and length L (2.5 m) extends horizontally from a wall and connected to the wall by a pivot (F is...

Homework Statement A hollow metal sphere has 6 cm and 10 cm inner and outer radii, respectively. The surface charge density on the inside surface is -100 nC/m^2. The surface charge density on the exterior surface is + 100 nC/m^2 . What is the strength of the electric field at point 4 cm from...

Hi all, It is my understanding that the color of a material results from the inability (or lesser ability) to absorb in that particular wavelength. Reading Atkins' "Physical Chemistry" (8th ed.), I run into a statement I couldn't quite get. On page 730 (chap. 20), he states the following...

Question is Why does a desk lamp often has small holes near the top of the metal lampshade. How do these holes keep the lamp cool. This is what i think. Heat travels upward by air convection. Since air is a poor conductor, very little heat travels sideways. That is my reason what do u...

A question about metal thermo flasks, or metal vacuum flasks if you prefer. I understand the principle of thermo/vacuum flasks. Just to proofed that I read up before posting this question :-) http://en.wikipedia.org/wiki/Vacuum_flask But today I had a look at on of those new-isch thermo...

can someone explain to me why reactive metals will form stable compounds with strong bonds? any help will be much appreciated

Suppose one has a solid metal body (in static eq'm) with a cavity inside it. Assume the cavity has no charge in it. This is how one could prove that there are no fields inside the cavity: choose two points A and B, both in the solid part of the metal body. Follow a path through the metal...

hey does anyone know how you can carry out an experiment to find out if a metal or non-metal has a metallic lustre?:confused: i have tried looking all over the internet but i can't find anything... if u could post answers or terms i can place into the google search panel it would be greatly...

If you drop a metal ball and a feather at the same time the ball will touch the ground before the feather, why is this? What effect is the Earth's atmosphere having on the feather? If you dropped a piece of metal in the shape of a feather it still would touch the ground before the feather and...

Homework Statement This is a Problem 7.7 fom Griffiths Introduction to Electrodynamics (3ed) A metal bar of mass m slides frictionlessly on two parallel conducting rails a distance l apart. A resistor R is connected across the rails and a uniform magnetic field B, pointing into page...

Hi All, my friend has a big chunk of Copper Iridium metal. It attracts all non-metals like paper, wood etc and reduces it to powder. It is not a magnet because it does not attract iron. Can someone please explain this phenomenon ? Please forgive me if I am in the wrong forum. I am totally...

We have a bunch of very strong pictures for this contest. Let's see if we can decide our favorite. Please vote for the picture that best represents our theme, which is on metals. 1. turbo-1 2. Integral http://home.comcast.net/~Integral50/Photo_contest/HPIM2549a.JPG 3. larkspur...

Thanks to Evo for graciously running the PF Photo Contest while I was on vacation. Heavy Metal Think "industrial". Your picture must have, as its main subject, something metallic, made of metals. This could be iron, steel, copper, alloys, etc. If it isn't clear, please include a brief...

I was reading there that if you wind a piece of metal wire into a coil it creates a magnetic field. Does this wire have to have current running through it? I know that a changing electric current creates a magnetic field but how does winding a piece of metal wire into a coil create magnetic flux?

Homework Statement Ok this one is easy I just want to make sure: A metal of mass M is in a smelter at temperature T_{o}. How much heat does it take to melt the metal. Given: heat capacity, melting point T_{m} Homework Equations Q=Mc\Delta T The Attempt at a Solution So it would be...

I am wondering if: 1. Is it possible to design such system? I am trying to induce the Aluminium Tin, then deflect it using a positively charged metal plate. 2. If so, what is the cost needed? Let say I want to deflect the tin for about 5cm from the center, and the size of the design should...

I have a pictorial example in a book here of a solid that behaves very strangely indeed. I would have called it 'biaxial metallicity' but I have no idea what the correct term is - the material is apparently metallic in one direction but not in another - that is, appears to obey the free or...

I was reading the plasmon chapter of my solid state physics book and it says simple metals should reflect light in the visible region and transmit it in the ultraviolet, roughly speaking. (I think I read in a paper that for some metals, like Au and Cu, the threshold wavelength is in the visible...

Can microwaves melt metal? As far as I know, it can't melt a spoon no matter how long you put it in a microwave oven. Is it possible to get microwaves to melt metal?

Hi everybody I am not so sure if this question is suitable to be in this box, but I hope it is. I know that all metals are opaque because they have lots of free electrons which absorb the energy of photons. But a polished surface of metal reflexes light other than absorbs it, especially...

I'm interested in hearing what metal bands you guys like. I like death metal so my favorites are: Kataklysm, Amon Amarth, All that Remains, and Scar Symmetry. List your bands and some vids. here are mine: http://youtube.com/watch?v=3rfTqmX6f3k This vid is a video of Martin Maurais (kataklysm...

I need help solving this question: The magnetic flux through a metal ring varies with time t according to B = 3( at 3 - bt 2) Tm2, with a = 2.00 s-3 and b = 6.00 s-2. The resistance of the ring is 3.20 . Determine the current induced in the ring at t = 1.00 s. I know that you have to take...

This is a good one. We all know that in an ideal gas, there is no isothermal potential energy stored when you do work on the gas. Compress the gas: all the work appears as heat, and when you cool to ambient, it's all gone. Compressed ideal gas stores no work EXCEPT as heat. Now, less well...

can anyone help me interpret what exactly this question is asking as i am quite unawares By direct substitution into the heat equation and calculation of boundary values, verify that the solution u(x, t) for a metal rod of length L which satisfies the initial temperature u(x, 0) = f(x) and...

Why is it that when there's transfer of charge onto the metal it always forms on as close to the surface as possible and in a thin sheet?