Copper Definition and 513 Threads

Maybe this topic has already been discussed, and that I've just missed it. Is there any scientific proof or theraputic evidence that either magnetic or copper bracelets work in relieving rheumatic or arthritic pain?

Homework Statement I need to find the total number of water molecules per copper sulfate molecule. The answer is 5. But, I keep getting ~4 with the average of two dehydrating experiments. 2. Homework Equations with my Attempts I am just using simple factor equations for these. I am...

Where did the copper and tin come from? this article suggesrs that copper could have been mined in America 3000BC and transported to Europe. http://www.philipcoppens.com/copper.html

How many copper atoms are there per grain? What is the volume of a grain of metal containing 1020 copper atoms?

Homework Statement We know that, within the limits of measurement, the magnitudes of negative charge on the electron and the positive charge on the proton are equal. Suppose, however, that these magnitudes differed from each other by as little as 0.00010%. With what force would two copper...

Homework Statement A 150 km long high-voltage transmission line 2.0 cm in diameter carries a steady current of 1030 A. If the conductor is copper with a free charge density of 8.9 1028 electrons per cubic meter, how many years does it take one electron to travel the full length of the cable...

Homework Statement Copper can be drawn into thin wires. How many meters of 34-gauge wire (diameter = 6.304 x 10^-3 in) can be produced from the copper in 5.01 lb of covellite, an ore of copper that is 66% copper by mass? (Hint: Treat the wire as a cylinder. d of copper = 8.95 g/cm^3)...

Homework Statement Brass is an alloy of copper and zinc. Varying the mass percentages of the two metals produces brasses with different properties. A brass called yellow zinc has high ductility and strength and is 34%-37% zinc by mass. (a) Find the mass range (in g) of copper in 185 g of...

I am having trouble understand the crystal structure or copper oxide and what the first brillouin zone looks like.

Hi, I'm trying to get balsa wood to burn green, and I know that copper burns green. If i cut up pieces of copper and dissolve them in water, then let the balsa wood soak up the water, I imagine it would burn green. However, I don't know if I can dissolve copper in water. I would appreciate...

I have a question because of something I remembered while I was looking at some large copper windings for a generator. I heard one of my teachers say that electricity moved along the surface of a copper wire. I am wondering how pitting a copper wire, making it sponge like, or carving...

Homework Statement A square loop, 5.3 m on a side, is made of copper wire, 0.9 mm in radius. A 3.2 T magnetic field, perpindicular to the loop is increasing at the rate of 0.29 T/s. The resistivity of copper is 1.7 x 10^-8 ohm*m. Find the induced current. Answer in units of A. Homework...

Homework Statement a piece of copper wire (rho_20 = 1.7*10^-8 ohm-m) is being used as a resistance thermometer.At 20 degrees celsius, the wire is known to have a resistance of 170 ohms. when the wire is immersed in a hot oil bath, its resistance increases to 173.4 ohms. if the temperature...

Homework Statement a cylindrical bar of copper has a resistance of 0.02 ohms a) if the power of the bar is 10000 watts, what is the maximum current the bar can carry? b) the bar is now stretched to 3 times its original length, while the total volume of the bar remains constant. what is...

Homework Statement X-rays 1.54 angstrom reflected off copper powder @ 21.65º 25.21º 37.06º 44.96º 47.58º Homework Equations nλ = 2d sin(Θ) ; the Bragg equation The Attempt at a Solution The cubic latice is face centered at d110? 5 planes? I tried plotting...

Hey all, I was wondering about a varied version of something. I know that if you run a magnet up and down a tightly coiled tube of copper, it creates an electric current through the wire. I also know the reverse, which is that if you passed a current through that wire, while it was wrapped...

Not just free electrons, ALL electrons. How strong would that be?

Homework Statement A copper calorimeter can with mass 0.100 kg contains 0.160 kg of water and 0.018 kg of ice in thermal equilibrium at atmospheric pressure. If 0.750 kg of lead at a temperature of 255^{o}C is dropped into the calorimeter can, what is the final temperature? Assume that no...

[SOLVED] Find the diameter of copper wire Homework Statement Find the diameter of copper wire which has the same resistance as an aluminum wire of equal length and diameter 1.2mm. The reactivities of copper and aluminum at room temperature are 1.7x10^-8Ωm and 2.6x10^-8Ωm respectively. Can...

[SOLVED] Electromagnetic induction Homework Statement You are given the following apparatus: copper ring, battery, variable resistor, lengths of insulated copper wire with connecting terminals at each end. Describe, how you would use all of this apparatus to induce a current in the copper...

Homework Statement I'm supposed to calculate the youngs modulus of a 2 meter length of copper wire. Homework Equations None The Attempt at a Solution for 30SWG i get 26GPa for 38 i get 3.1 GPa and for 24 i get 49 GPa Youngs modulus of copper is meant to be ~100GPa (from wiki)...

I’ve learned that copper wire is not generally used in a potentiometer. Is there any specific reason for this?

[SOLVED] Hookes law equation for all gauges of copper wire Homework Statement For my coursework I'm trying to find an equation using hookes law that works with all gauges of copper wire, i know that this means i will have to change the hookes law equation from F=ke to F=ake (a is not the area...

Question Details: In the figure the top wire is 1.1 -diameter copper wire and is suspended in air due to the two magnetic forces from the bottom two wires. The current is 50 in each of the two bottom wires. Calculate the required current flow in the suspended wire. i have been working...

Homework Statement I have to find the energy removed through conduction from a copper pipe. Pipe Inner Diameter (Din): 8mm Pipe Wall Thickness (Dout): 1mm Thermal Conductivity (k): 401W/m.K Temp inside pipe -150C, Outside 30C Length (L)=1m Homework Equations The Equation I used was...

Homework Statement A copper penny falls on a path that takes it between the poles of a magnet. Does it hit the ground going faster, slower, or at the same speed. The Attempt at a Solution Clearly the penny undergoes a change in magnetic flux. Since it receives a change in magnetic flux...

Homework Statement Calculate the reflection coefficient of copper for radio waves at frequency 50Ghz and yellow light (wavelength = 0.6 micrometers) Homework Equations Reflection coefficient: R = E(r)^2/E(I)^2 = (1-n/1+n)^2 Where E(r) is the electric intensity of the reflected wave...

Just looking through some old papers and found a problem that I don't know how to solve. Two identical 1.0-kilogram blocks of copper metal, one initially at a temp OC and the other initially at a temp of 100C are enclosed in a perfectly insulating container. The two blocks are initially...

Hi all, Biologist posting here. We have a thermal gradient that doesn't seem very stable. Right now, our setup is the following: hot water runs through one aluminum bar and cold water runs through another. the two bars are about 25cm apart. There is a thin aluminum plate resting on the...

Hey all, I have a pretty straightforward question about electron mobility in metals. We are given the length of a copper wire, it's radius, the current flowing through it, voltage drop across it, and the proportion of free electrons to copper atoms. I've found the current density...

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...

I'm trying to understand a bit more about high temperature superconductors. I'm familiar with BCS theory and a little bit about high temp superconductors, but I'm still confused about a bunch of stuff Why exactly is copper oxide used in high temperature superconductors? Why is this specific...

Strontium Chloride + Copper (II) Sulphate Pentahydrate --> ? Well, I did a lab in class a few days ago, where we were to react Strontium Chloride with Copper (II) Sulphate Pentahydrate, and determine what the precipitate formed was. Here's how the lab worked. We took 2.00g samples of each...

[SOLVED] Chem Lab Help! My AP chem class did an experiment where we started with 0.500 grams of copper and we ended up with 0.525 grams of copper after the experiment. The experiment consisted of us sending copper through different reactions to observe the effects of a series of reactions on...

Calculate the force required to pull a copper ball of radius 3.00 cm upward through a fluid at the constant speed 9.00 cm/s. Take the drag force to be proportional to the speed, with proportionality constant 0.950 kg/s. Ignore the buoyant force. For this question, do I have to find the mass of...

Okey, I have a problem now. I´m suposed to sketch a graf of how long range on a copper wire some different speeds have ex 256 kbit/s etc. I have 225 channels of each 4kHz and it can transfer 4000 symbols/sec. The effect on each channel is 0.1mW and the noise is -100dBm. The signal is...

Why do they say that copper wires are more conductor than aluminium wires?

Hi there! Can anyone help me with a problem. I did an experiment at school trying to measure the Young's modulus of a copper wire. We attached one end of the copper wire to a clamp and then tied on weights of 100g at a time to the other end so that a force can be applied to the copper wire...

A piece of copper wire has a resistance per unit length of 6.40e-3 ohm/m. The wire is wound into a thin, flat coil of many turns that has a radius of 0.190 m. The ends of the wire are connected to a 12.0 V battery. Find the magnetic field strength at the center of the coil. R/L = 6.40e-3...

I have a copper coin with a hole in the centre. The hole is a circle. If the coin is heated, the metal will expand towards all directions in and out, so the radius of the circle will be decreased. Correct?

Hello there I'm currently working on an EM device that should be able to measure the humidity in the ground. I cannot give too many details, but let's consider the following issue: I have a copper closed loop in which I send some current to generate a magnetic field. But there are some EM...

i just recently acquired a few pieces of copper impregnated graphite. this stuff is supposed to have high wear resistance in EDM applications So i thought i would give it a shot in a chlorate cell. After a few minutes of operation my electrolyte which is a solution of KCL, turned blueish green...

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...

A copper pipe has an inside diameter of 6.720 cm and an outside diameter of 8.000 cm. What length of this copper pipe will have a resistance of 8.05 × 10-3 W? so i am using the equation R=rho(L/A) A=pi(d2-d1)^2/4 which is 1.29E-4 m and for copper rho is 1.7E-8 so...

please help me solve this... fermi energy of copper is 7eV. what is the fermi momentum of an electron in copper? what is the de Broglie wavelength of the electron? what is the fermi velocity?/// please help/////:cry:

A cylindrical aluminum pipe of length 1.36 m has an inner radius of 1.80 10-3 m and an outer radius of 3.00 10-3 m. The interior of the pipe is completely filled with copper. What is the resistance of this unit? (Hint: Imagine that the pipe is connected between the terminals of a battery and...

Homework Statement A 85.0 g hollow copper cylinder is 70.0 cm long and has an inner diameter of 1.0 cm. The current density along the length of the cylinder is 1.20×10^5 A/m^2. What is the current in the cylinder? Homework Equations possibly J = I/A where J is the current density The...

Hello All, Is there a way to predict the speed at which an electrical potential travels through a piece of copper wire? I know that the electrons themselves move very slowly (at the drift velocity), but how about the voltage potential itself? Are there any nifty equations out there to...

A piece of stiff copper wire hangs from a metal between the jaws of a u-shaped magnet and its free end dips into a pool of mercury. Mercury is connected to a positive terminal. piece of stiff wire will move: A towards the south pole B towards the north pole C to the right towards the support...

Two days ago in my physics class, one of my friends asked me a question: "There are 2 identical circular coils with radius 'r', length 'l' and 'n' no. of turns placed with their axes lying on a straight line, and current is let to pass through them so that mutual induction is observed.What...