Metal Definition and 999 Threads

If you put a piece of very hot metal in cold water the heat in the metal will transfer to the water until both are the same temperature. So the system water-metal still has the same initial energy. So my question is how does the piece of metal cool if it is put on a perfect vacuum. Is it...

Homework Statement I have always been told to remove anything metal before walking through a metal detector. Why is it bad to take a laptop through a metal dector? How can I give me answer in the language of physics? I cannot just say that it will probably scramble my internal memory and...

A square rigid metal frame PQRS, of side 12 cm, forms a closed circuit with an ammeter. It is moved through an enclosed region of uniform magnetic field of flux density 2.0 × 10–2 T, from left to right. The field is confined to this area and directed into the page. PQRS --> magnetic field -->...

I want to use an "inductive proximity sensor" for metal detector gate, but the problem is its range is (generally) under 50mm (2 inches), is there any way I can increase its range? or is there any alternate sensor or way to detect the metal ? Thank you. Faraz Nizamani

Homework Statement What is the density of lithium metal in g/cm^3 if a cylindrical wire with a diameter of 2.40mm and a length of 15.0cm has a mass of 0.3624g?Homework Equations D=m/VThe Attempt at a Solution The problem I'm having is I don't understand what the problem is asking. How do you...

Homework Statement A metal sphere centered at the origin has a surface charge density that has a magnitude of 24.6 nC/m2 and a radius less than 2.00 m. At a distance of 2.00 m from the origin, the electric potential is 540 V and the electric field strength is 270 V/m. (Assume the potential is...

I roughly understand that when we hit a metal rod right into the end will excite longitudinal vibration in the metal rod, and the place we hold will be a node. the position i hold will kind of determine the frequecy of the ringing sound produced. Is that right? But what will happen if we hit...

I have an electrode that I'm trying to model. It's got v=0 at z=0, and v=V at z=H. I've been playing around with the poisson equation, and keep getting terrible solutions to PDEs involving Bessel functions. Anyone know if there's a better way to do this (since I can't seem to solve it with the...

I was just curious of something and was wondering if anyone could shed some light on this. I have a metal screen (like the kind you have on your water taps). I think it is made out of steel or something? Anyways, I was bored one day so I put a lighter up to it till it started glowing red...

At first I thought it would be ridiculous to ask this question in a forum but, in reality it's probably the best place ironically. (background information) I am a recent college graduate. Metal Casting technician. 26 years old, and basically decided to self-cure my Social phobia. No offense to...

A free-hanging, easy ball to the surface coated with aluminum foil, recharged by a metal rod, one end of which affect the ball (figure A). Charge is introduced with metal rods the other end, as it touches with a charged coating rod. The ball makes rulings that show that the metal rod and had...

I am with a search team who use Mobile Signal to guess the whereabout of missing persons. I was told that for 900MHz GSM Signal can go as far as 30km if weather permits. I know where the station "B" is, it is about 20km away from my current location "A". At "A", I can receive somewhat...

Just wondering, how could you influence the number of photons emitted from a metal surface. I would assume that increasing the intensity of the light would cause an increase because the intensity is a measure of the amount of photons traveling in the light. But what about other factors such as...

Hello, Chemistry grad student here about to start a physics-y project...so trying to learn about condensed matter physics. I get how screening works when you add a single charge to a gas of electrons, but what happens in a metal when you have a whole lattice, ie, a background charge density...

I have a problem I can't seem to solve. here it is and here is what I have gotten. Iron metal is produced in a blast furnace through a complex series of reactions the involve reduction of iron(III) oxide with carbon monoxide a. Write a balanced overall equation for the process, including the...

Hello, I've read that metal film resistors are better than carbon film because they're resistance remains constant even when they heat up from being soldered. And I know they're suppose to be more precise with a 1% variance instead of 5% of the carbon films. I know capacitors go bad - do...

Please see title

How do I find the total electron count in a transition metal complex? For example, something simple like W(CO)6 or even more complicated like RuH(Cl)(PPh3)3? (Note: I don't mean "d electron count" [which I know how to find], I mean "total electron count.")

Dear Gurus, :) I am not sure what metal is suitable for the following kind of application: 1. this metal should allow a magnet to stick on to it via magnetism. 2. when the magnet is removed from this metal, it should not be magnetised in any way. That is, after using it with a magnet...

Hi people, I have a question which i hope you helpful guys/gals can help to shed light on. We all know when we strike one end of a solid metal rod with a hammer sideways (i.e. from left to right), longitudinal vibrations will be set up across the length of the rod. Textbooks and websites...

Hello friends, I have done some research on the Internet about producing standing waves in a metal rod, and how the various harmonics frequencies are being derived. I have two questions that i wish to discuss here: 1. Is the pattern of standing waves and method of formula derivation the...

2 metal, thin, bars (length=l, mass=m) are hunging on same height (distance between bars-d) Lower end of bars are conected by metal spring (mass=0, k-spring constant, d-length) My problem is how to calculate a normal mode.

The bullet hits near the top of block. Which will tip the block over? Which will do most damage? I believe the rubber will tip it over and the metal will do the most damage...but I'm not sure how to explain it. When the metal hits it enters the block. When the rubber hits there is a...

Homework Statement A thin square (4 ft side) metal sheet of homogeneous density (\sigma = M/Ais rotating around one of its diagonals at 10 rev/s. Develop a definite integral to express its kinetic energy. Homework Equations dK = \frac{1}{2}(r\omega)^{2}\sigma dA The Attempt at a...

Homework Statement Two concentric metal spheres have radii R1 =10cm and R2=10.5cm. The inner sphere has a charge of Q=5 nC spread uniformly over its surface, and the outer sphere has charge −Q spread uniformly over its surface. Calculate the total energy stored in the electric field...

Homework Statement A 100-g piece of metal initially at T = 75oC is submerged in 100 g of water initially at T = 25oC. The specific heat capacity of iron is 0.45 J g-1 °C-1 and the specific heat capacity of water is 4.18 J g-1 °C-1. What is the final temperature of both substances in oC...

I want to take a liquid metal, Aluminum at 700oC and pour it into a steel mold starting at 20oC. For the purpose of the question let’s say that the heat transfer is 100% with no losses to the surroundings. Here are some numbers: Al Mass = 200 g = 0.2 Kg Ti, Al = 700oC Cp = 900 J/Kg-K...

I just noticed that Li is higher on the activity series than K, which is higher than Na. I thought that the activity series was related to the reactions between the group I metals and water, but the series doesn't correspond with the energy produced by the reactions. I'm definitely missing...

Homework Statement Figure 7-29 shows a composite slab with dimensions 22.0 cm multiplied by 13.0 cm multiplied by 2.8 cm. Half of the slab is made of aluminum (density = 2.70 g/cm3) and half of iron (density = 7.85 g/cm3), as shown. How far from the line joining the two metals is the center...

Homework Statement http://img35.imageshack.us/img35/6177/uthw404.jpg Homework Equations The Attempt at a Solution I tried finding the center of mass of the square as if there were no hole in it, and then I added the radius of the circle to the x-coordinate of that. It's wrong...

Homework Statement https://www.physicsforums.com/attachment.php?attachmentid=21003&stc=1&d=1255013927 I need help for number 11(b), (d) The Attempt at a Solution (b)(i) Electrons move towards the right since like charges repel. (ii) Unlike Charges attract. Thus, positive...

Hello! I just registered on these forums and this is my first post here, so hopefully I did everything right. I recently got into metalworking in my spare time, and I am trying to create a metal alloy that will remain liquid at room temperature (a fusible, eutectic alloy). From what I've...

Metal Detectors! Guys I an Undergraduate student in Lancaster University (England) and I have a passion for metal detecting when I am not in UNI. Over the years I have spoke many of my lecturers and research staff about the depth of a metal detector and its soul destroying ability to pick up...

first of all, i not sure whether this question should be posted here. seem the soil is more related to chemistry. :confused: Is Fe the highest concentration in the experiment extraction of heavy metal from organic oxidation phase (OO phase)? If so, why? thanks for helping ya.:smile:

A few questions about electric field here: 1. Why do charges have to be on the outer surface of the conductor? 2. Why no charge on the inner surface of a hollow conductor? 3. If charges cannot be inside the conductor, how come the electric potential is constant throughout the conductor when...

Metal inside a microwave oven --> ice? When I was younger, I placed water inside a tin pan and placed it inside a microwave. I tuned it on, sparks went everywhere and I quickly turned it off. I took the pan out and it was solid ice. How? A while ago I read an article in New Scientist that...

I recently purchased a new microwave oven, and there's a metal rack in it. The salesmen informed me that it shouldn't cause any problems as long as it didn't touch the sides; however, he was unable to tell me why this is. I have a basic understanding of how microwaves(as in the radiation not the...

What is the size of iron pentacarbonyl, methylcyclopentadienyl-manganese-tricarbonyl, or dicobalt octacarbonyl? Where could I find a source on this information? I am aiming to fit the above carbonyls into a 29-34 angstrom pore, but I'd like to know if it's even possible given the size of the...

Homework Statement A small metal sphere, carrying a net charge of q_1 = -2.60 \mu C, is held in a stationary position by insulating supports. A second small metal sphere, with a net charge of q_2 = -7.70 \mu C and mass 1.40 g, is projected toward q_{1}. When the two spheres are 0.800 \rm m...

Homework Statement A Mg-Al alloy has a mass of 0.263 g and a density of 2.40 g/cm3. The density of pure Mg = 1.74 g/cm3 and for pure Al = 2.70 g/cm3. Calculate the % Mg in the alloy.Homework Equations D=M/VThe Attempt at a Solution Well I'm not really sure where to do. I solved for the volume...

Here's an interesting technology I came across: http://en.wikipedia.org/wiki/Alkali-metal_thermal_to_electric_converter So, from this I take it that a means of high-power conversion of nuclear thermal energy to electricity could be achieved. It says it only works upto 1400C, but that seems...

Homework Statement Two metal balls A and B of negligible radius are floating at rest on Space Station Freedom between two metal bulkheads, connected by a taut nonconducting thread of length 1.30 m. Ball A carries charge q, and ball B carries charge 2q. Each ball is 1.66 m away from a bulkhead...

Homework Statement Monochromatic light with a wavelength 415 nm strikes a metal surface. Photoelectrons escape with a kinetic energy of 95 kJ/mol. What is the work function (in kJ/mol, no decimals required) of the metal surface? Homework Equations I have found various equations online...

Homework Statement The speed of sound in a metal rod is 3600 m s -1. The rod is 1.20m long and clamped at one of its ends. (a) Determine the frequency of its vibration if longitudinal waves are established in the rod and it is vibrating in its first overtone mode. (d) Determine the...

There is a metal ball and a metal ring , through which the metal ball can pass easily. But when the metal ball is heated , it can't pass through the metal ring. What will happen if metal ring is heated?(keeping metal ball normal)

I am building a simple capacitor for experimentation and i have a question, or two. At the moment i am using 30cm x 30cm (1 sqft) aluminum plates with a minuscule gap in between them as a capacitor. At the moment, even at the 200micro amp setting on my ammeter I get a very low reading (about...

1. Calculate the density of Na metal. The length of the body-centered cubic unit cell is 4.24 Å.2. Attempted solution: [4 Na Atoms/unit cell] * [1 mol Na atoms/(6.022*10^23 atoms)] * [22.99g Na/1 mol Na] = 1.527 * 10-22 g/unit cell (4.24 Å)3 = 7.6225 * 10-23 cm3/unit cell[1.527 * 10-22 g/unit...

Does anybody happen to know what readily-available metal is the worst electrical conductor?

just wondering if its a sneaky answer or just as simple as put a magnet next to it?

i found the average specific heat of a metal through an experiment it is 200. my only problem now is identifying it. i have tried many website but can't find anything useful please make some suggestions