Metal Definition and 999 Threads

Suppose I have a closed end aluminum pipe of 3cm diameter with .5cm walls Cylinder is 10cm tall , 8mm of which is submerged in a cold bath of approximately constant temperature of -10°c I feel it with water at 3°c to 7cm height and stick a cork in it. How long till the water freezes...

So I had to have an MRI today and when your in the machine you wear these headphones so that they can talk to you and stuff, but how could they work with no metal? I realize that there are non-metal conductors but I thought that they had to be doped with metals (to make them semiconductors) so...

When a hand spray painting gun is used to paint say metal tanks, about 80% of the paint is lost in the air. This not only leads to a wastage of paint, but also the paint partivles settle on other stuff causing paint spots. What method can be used to reduce this? One is ionizing the tank...

I've had my phone messed up before by metal and I wondered what the metal did to my phone, I'm guessing it maybe grounded the battery but I'm not sure. Can someone explain what happens when a metal or magnet interacts with electronics? And also is there any way to fix this if that did happen to...

HI I am doing this equation : 14. When a certain metal is illuminated at 3.50x10^2nm the maximum kinetic energy of the ejected electrons is 1.20 eV. Calculate the work function of the metal. I did this: E=Ek+W W=E+Ek W=hc/Lambda -Ek =(6.63E-34J.s)(3.00E8m/s)/3.50E2m)-1.20eV =-1.2 That...

According to the theories that discuss gravity, if humans were to create a solid metal sphere with the same mass as Earth would it have the same gravity as earth? Would it have to be orbiting something and/or moving to have that same gravity? Or could it be stationary and have the same...

Homework Statement Consider a thick metal shell with inner radius a = 2cm and b = 4cm. The shell carries no net charge. A point charge of q = 3nC is placed at the centre of the shell. Find the total charged induced on the inner boundary of the shell. Find the total charge induced on the outer...

It's so expensive! I've received a few quotes. 1st quote was 12 inches wide by 12 inches long by .01 thick. 50$ I need 3 feet of that size. But wow that's expensive for a material that's 75-80% nickel. 2nd quote was 4 inches wide by 12 inches long by .01 thick. 27$ I would need 9 feet at...

I am trying to charge a system of two metal rods, of definite length, placed a certain distance apart. But before setting up the rods and hooking them to any battery, i wish to know the magnitude of charge that will be accumulated on the rods and what is the maximum possible charge on the rods...

Hi all, How can I excitation - ionization solid metal ? May by radioactive material which is too soft.

Homework Statement When a charge Q is given to an isolated metal plate X of surface area A its surface charge density becomes σ .When an earthed metal plate Y is brought closed to X ,find magnitude of surface charged density on inner and outer surfaces of X and Y. Homework Equations...

Hi there, How to write the reaction between water and chromium metal under standard (i) acid and (ii) base condition? Cr + 3H2O ----> Cr(OH)3 + 3e- + 3 H+ (acid condition) basic solution ? Please help

I was thinking of a substance I could use to describe particle arrangement in solid/liquid/gas phases to school kids, and after realising water would be bad to use (since the liquid is denser than solid), I thought of using metal elements since they can exist in all phases. Basically the...

I'm in the process of designing an escape system that uses a metal rope. I'm hoping to use a stopper so that the cable is not pulled too far and came across the attached. Unfortunately i do not know the jargon to be able to research it (Possible Materials, strength, sizes, etc) and was hoping...

Homework Statement The graph in fig shows the stopping potential as a function of the frequency of the incident light falling on the metal surface. Find the photoelectric work function for this metal Homework Equations V_0 =\frac{hf}{e}-\frac{\phi}{e} The Attempt at a Solution...

Can anyone explain to me why most articles describe chromium as an acceptor in TiO2? In TiO2, titanium has the charge state Ti4+ and oxygen has the charge state O2-. When Cr substitutes for Ti, it does so as Cr3+. Now, at first glance, Cr has atomic number 24 and Ti 22. Cr therefore has two...

Lagrange Multiplier----to find out the dimensions when metal used min. Homework Statement I have a rectangular tank with a capacity of 1.0m^3. The tank is closed and the cover is made of metal half as thick as the sides and base. Find the dimensions of the tank for the total amount of metal...

Hello everybody I have designed two small metal pieces (approx 30x30 mm) currently in 3D design that I now want to prepare for production by casting/molding. They are both intended for mass production hence price is a big concern, even the very small designchanges that may lead to reduction of...

Hi everybody, Please forgive my question which is probably very obvious, but why are acids based on H ion concentration? Why is HCl a strong acid whereas LiCl is a salt. Both H and Li form + ions in solution. Conversely, why are OH- bases? Why can't NaCl be a strong base? I'm sure the...

1. Homework Statement I am trying to determine the limitations to my experiment and thus how to improve them. The experiment's objective is to determine the mass of a metal rod. The rod is balanced every time another 1kg is added onto the end of the rod. This means that the rod cannot...

Help with "Balancing a metal rod" experiment. 1. Homework Statement I am trying to determine the limitations to my experiment and thus how to improve them. The experiment's objective is to determine the mass of a metal rod. The rod is balanced every time another 1kg is added onto the end...

Stretch piece of metal within its elastic limit and it cools down. Does it cool down for the same reason that a gas cools down when expanded? But if the piece of metal is repeatedly stretched and released (like with a spring), I am led to believe that it heats up, although I am not sure. I know...

Dear all, I am a newbie in electromagnetic wave. Can you educate me, what will happen when an electromagnetic wave is blocked by a piece of flat metal placed in front of it? My intention is to build a thermal chuck using peltier for to measure femto amps from my device. I am worried if...

I saw a House episode where a person had internal bleeding because they had metal inside their body and they went into an MRI machine. I'm learning about NMR now and I want to try and understand it more.

What is the metal conductivity at ultraviolet frequency?

An ideal gas obeys Maxwell Boltzman statistics. Gas atoms have an average kinetic energy of 3kT/2 but the individual atoms have energies that vary from this average (Chi square distributed). A solid (metal) has an average kinetic energy of about 3kT. Does anybody know what statistical...

Is it possible to measure the resistance across a wire mesh with a multimeter? Thanks.

Homework Statement A hollow metal cylinder has inner radius a, outer radius b, length L, and conductivity sigma. The current I is radially outward from the inner surface to the outer surface. Find an expression for the electric field strength inside the metal as a function of the radius r...

Homework Statement A metal sphere of radius 10 cm carries a charge of +2μC uniformly distributed over its surface. What is the magnitude of the electric field due to this sphere at a point 5.0 cm outside the sphere's surface? 8.0 x 109 N/C 4.2 x 106 N/C 8.0 x 107 N/C 4.0 x 109 N/C 4.0 x...

When a light wave of the form E=E0eiω hits the surface of a metal, the refractive index if given(considering restoring force of metal atoms and damping equal to 0), by n2=1-p2/ω2 where p=plasma frequency and ω= frequency of the wave. In the case where n2<0, n is complex. and hence the light wave...

I'm not taking this course for credit... Hi! Is this a good text after Halliday? I'm trying problem 7.7- a metal bar of mass m slides frictionlessly on 2 conducting rails... perhaps the current is I=integral J dot da, generated by the moving metal bar, velocity v (results in changing reference...

All I understand clearly that if a metal sphere is charged then the charges must reside on the surface because that is the only way there is no electric field within the metal. However if you imagine a neutral metal sphere, and let's say it is suddenly enclosed by a uniformly charged metal...

Homework Statement A ring of aluminum has a hole in the middle. When the ring is heated: a) the hole decreases in diameter b) the aluminum expands outward and the hole remains the same size. c) the area of the hole expands by the same percent as the area of the aluminum. d) the area of...

I'm studying the dispersive properties of metals using Lorentz-Drude model, but I'm confused about the equation set-up. What is LD model different from the classical dielectric function using for other dielectrics? Namely: ε(w) = ε’ + iε’' where the imaginary part is the attenuation. In...

Homework Statement A metal rod (1/sqrt(pi)) m long rotates about one of its ends in a plane perpendicular to magnetic induction of 5*10^-3 T. Calculate the number of revolutions made by the rod if EMF induced between the ends of the rod is 1.5 mV. I have been thinking about this problem for...

What causes flame color? I know light color corresponds to photon energy which is related to electrons relaxing from a high to low energy state. I'm not sure how to conceptualize this situation though. My professor was heating a 0.8 wt% carbon steel rod, in austenite phase, with a blow...

In DC motor or even in AC motor, if we use wooden frame and shaft, would it be advantageous than using Metal frame and shaft? Assume that would can with stand any temperature.

Hi, Lets say I have two metal circular plates of diameter about 10mm. If I press them together with a force of about 1-10N at temperature of 4K and hold them like that for couple of hours, will it be possible to separate them apart again at 4K (same environment) using no force (less than 1N) or...

Homework Statement Two very small metal coated foam spheres, each of mass 2.80x10^-6kg, are attached to nylon threads 45cm long and hung from a common point. When the spheres are given equal quantities of negative charge, each supporting thread makes an angle of 15 degrees with the vertical...

Homework Statement Two metal plates are placed in parallel, 2mm apart. They are then connected to a fully charged 9V battery. Without discharging the plates, the battery is removed, after which the separation between them is increased to 1 cm. What is the new potential difference between the...

When a metal gets polarized it looks like this: http://postimage.org/image/bkdw8ttgn/ However, only the electron moves towards the positive ion. Why is this so? As both experience an equal force despite the different accelerations, shouldn't both the positive ion and negative electron come...

Homework Statement A metal sphere of radius r0 = 0.29 m carries a charge Q = 0.90 µC. Equipotential surfaces are to be drawn for 100 V intervals outside the sphere. Determine the radius r of the following equipotentials from the surface. a) first:___m b) tenth:___m c) 100th:_____m...

Hey everyone, In the process of wrapping my mind around the properties of metals for a realistic rpg combat system I'm working on, I made the following chart. Let me know what you think, if it's right (arrows pointing the right direction, covering the region, labeled correctly, etc), and if...

Homework Statement 2)Both, a brass tube and the steel rod located inside the brass tube are solidly attached to common end plates A and B at either end. The respective diameters are : Do = 5.4 [cm] Di = 3.0 [cm] d= 2.8[cm] Brass: alpha=19x10^-6/degree celcius E=210GPa Steel...

I was reading lately about fast reactors, breeders, and desirable high-temp reactors; and it seemed most new reactor concepts being studied today are more difficult than existing reactors in at least one way. Supercritical water reactors need to battle with ever more hot and high pressure...

Homework Statement Two concentric metal shells of radius a and b respectively ( a < b) are separated by weakly conducting material of varying conductivity σ(r) = kr where k is a constant and r is the distance from the common center. If the metal shells are maintained at a constant...

Homework Statement One end of a metal rod is maintained at 100°C, and the other end is placed in a large container with ice and water at 0°C. The rod has length 50 cm and a cross-sectional area of 0.8 cm 2 . The heat conducted by the rod melts 4 g of ice in 5 minutes. Calculate the...

Homework Statement I understand how metallic oxide dissolve in water to produce OH- ion due to high electronegativity of oxygen. But I am having trouble understanding how non-metallic oxide dissolve in water to form acid? For Homework I have to explain the reaction of Sulfur trioxide in water...

I'm trying to think about what it is I should be considering before I start throwing up some maths. I'm thinking to assume that the positively charged core is a point charge +e and the electron is uniformly distributed over a sphere of radius Rs. The self energy of the electron...

Homework Statement Describe the ”conduction band” in Na metal. Why it is half-filled and non-magnetic? The Attempt at a Solution Na has electron configuration: [Ne]3s^1 the 3s band is highest in energy and is the conduction band for Na. since Na has 1 electron in the 3s band, and...