Copper is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement.
Copper is one of the few metals that can occur in nature in a directly usable metallic form (native metals). This led to very early human use in several regions, from c. 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, c. 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create bronze, c. 3500 BC.In the Roman era, copper was mined principally on Cyprus, the origin of the name of the metal, from aes сyprium (metal of Cyprus), later corrupted to сuprum (Latin). Coper (Old English) and copper were derived from this, the later spelling first used around 1530.Commonly encountered compounds are copper(II) salts, which often impart blue or green colors to such minerals as azurite, malachite, and turquoise, and have been used widely and historically as pigments.
Copper used in buildings, usually for roofing, oxidizes to form a green verdigris (or patina). Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as bacteriostatic agents, fungicides, and wood preservatives.
Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the respiratory enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the iron-complexed hemoglobin in fish and other vertebrates. In humans, copper is found mainly in the liver, muscle, and bone. The adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight.
Help me explain how the "magnet dropped down a copper tube" demo conserves energy
I've tried explaining to this person that the potential energy you give a magnet when you do work against gravity to raise it up to the copper tube is all the energy it has to deal with, and once dropped down it...
1. A piece of copper whose density is 8.93 gm/cm^3 weighs 180 gm in air and 162 gm when submerged in a certain liquid. What is the density of the liquid?
2. d = m/v
3. I wasn't sure how to compute this but I calculated the volume of the copper based on its density and air weight...
In my table lamp, there is only a switch, and a copper coiled sheets of steel. I am in K9 and would like to know what are those sheets for ?
My second very fundamental question is when should we use an adapter ?
Thank you
Got exams in January so just want to make sure I am correct the questions read exactly like this
a) The sample of copper wire reached its elastic limit when the stress is 1.4x10^8 Pa and the strain is 0.035 Calculate the Young's Modulus for copper.
My attempt is Y= Stress/Strain => Y=...
1. Homework Statement
10) Both iron (III) oxide and copper (IV) oxide are mined for use as primary ores in the production of pure iron and copper respectively. Historically, the earliest use of copper tools appears to be around 4500 BC. Iron tools appear much later; European artifacts have...
Has anyone ever considered this issue with magnet falling in copper tube??
Homework Statement
I must explain why a magnet falling in a copper tube slows down.
Homework Equations
F = B^qv
However, I must *explain* this, I don't have to calculate anything
The Attempt at a Solution...
Homework Statement
How far does an average electron move along the wires of a 299 W toaster during an alternating current cycle? The power cord has copper wires of diameter 1.7 mm and is plugged into a standard 60 Hz 120 V ac outlet.
Homework Equations
Prms=IrmsVrms
Ipeak=I0=Irms(sqrt...
Homework Statement
A 20cm^3 block of lead and a 20cm^3 block of copper are completely under water. Each is suspended by a thread so that they both hand at the same height in an aquarium filled with water. Which of the following is true?
a) The buoyant force is greater on the lead than on...
Homework Statement
A vertical, 1.13m length of 18-gauge (diameter of 1.024mm) copper wire has a 200.0N ball hanging from it.
What is the wavelength of the third harmonic for this wire?
A 1000- ball now replaces the original ball. What is the change in the wavelength of the third harmonic...
The drift speed of the electrons in a copper wire running from a battery to a light bulb and back is approximately 0.020 mm/s. The battery is at the front of the classroom and wire runs out of a perimeter of the room to the light bulb. The total length of wire is 40meters. How long would it take...
I understand \vec J_{free} only exist on boundary surface of perfect conductors. Copper is close enough and have surface current. Also copper is paramagnetic material which implies \mu_{cu} = \mu_0 or very very close.
In order to find the exact angle of the of the magnetic field inside the...
Homework Statement
A copper wire is 9.00 m long and has a cross-sectional area of 1.00 10-4 m2. This wire forms a one turn loop in the shape of a square and is then connected to a battery that applies a potential difference of 0.100 V. If the loop is placed in a uniform magnetic field of...
Homework Statement
Estimate the mean drift velocity of a conduction electron in copper, assuming that there is one conduction electron per atom. Consider No. 14 wire (diamter 0.16 cm), common in houses, carrying 5A. The result should be very small. Why then does an electric light turn on...
Homework Statement
A copper cylinder is initially at 20.0 degrees c At what temperature will its volume be 0.150 % larger than it is at 20.0 degrees c
Homework Equations
delta v = Beta vo (delta T)
dv= beta vo dtThe Attempt at a Solution
ive found an answer of 49.41 degrees c
I believe its...
1. Homework Statement
An Ideal gas and a block of copper have equal volumes V and at the same temperature T and atmosphere pressure P. The pressure on both substances is increased reversibly and isothermally to 5P.
a) Find the work done on the ideal gas if V = 0.5 m and T= 300 K P =...
Homework Statement
An Ideal gas and a block of copper have equal volumes V and at the same temperature T and atmosphere pressure P. The pressure on both substances is increased reversibly and isothermally to 5P.
a) Find the work done on the ideal gas if V = 0.5 m and T= 300 K P =...
I'm looking for a good article or string that would help me win a bet with a friend that is occasionally accurate...but not on this. Does anyone have any advice as to how to prove that I'm the winner of this bet? The bet is based upon a discussion as to why my brand new liquid-cooled heat sink...
Homework Statement
In our lab recently we measured the resistance of copper as a function of length. I plotted a graph with resistance as the dependent variable and length/area as the independent variable. I know the slope of the best fit line is equal to the resistivity of copper and that...
Homework Statement
This isn't really a homework question, but it is part of a lecture powerpoint that the teacher will go through with on Monday and I was just getting ahead so I can understand better.
[PLAIN]http://img59.imageshack.us/img59/3088/cuelectronconfig.png
Homework Equations...
Homework Statement
The density of copper is 8930 kg m-3, its mass number is 63.55 and its atomic number is 29.
a) Calculate the mass of a copper atom in kg.
b) How may electrons and protons does a copper atom have?
c) Estimate the diameter of a copper atom from...
Homework Statement
Find the resistance of a 1.4 m length of copper wire with diameter of 5*10^-3 m.Homework Equations
R = p(L/A) where p = resistivity of copper, L = length, A = areaThe Attempt at a Solution
The resistivity of copper is (1.69 * 10^-8). Radius is d/2 (5*10^-3) / (2) =...
I wanted to know how the magnetic field of a solenoid would be affected if a copper/iron pipe section was put into its center. In other words, what would the resulting magnetic field be if I simply wrapped a coil around a metal pipe section without removing the pipe afterward?
Will there be...
Homework Statement
You have 2 magnets separated by a distance. The top magnet has its south end facing the north end of the other magnet thus forming a magnetic field. Finally you insert a loop of copper wire (the pic shows a copper tube though) between the two magnets with the open ends...
Homework Statement
The rotor of a 3 phase 60hz 8-pole induction motor takes 220w @ 3hz. Find the rotor speed and the rotor copper losses.
2. The attempt at a solution
I have found the rotor speed by using the equation slipspeed = fr(120)/P = 3hz(120)/8 = 45 rpm then finding nsync by...
I hope someone can help. I am an Production Engineer. We have a situation where we have to torque a 16mm copper cable in a box terminal by 4Nm. The cable will be used to carry a high electrical current.
We find that after torqueing (About 5 hours or so) the terminal can be re-tightened back...
Good Day,
I have defective Aluminium windings motor.
As you know Aluminium is very difficult to winding.
So, I want to use Copper wire to re-winding the motor.
How can I do that?
What size should I use and what will be the number of turns?
Someone told me that you can use...
I got a small conserning how to determine if a object is solid or hollow.
"Verify if a copper object with density of 8,96 g/m^3, which weights 2,8N on the air and when submersive on water (p=998 kg/m^3) weights 1,3N, is it solid or hollow?"
Homework Statement
A 1.0 cm copper wire of diameter 0.10 cm carries a current of 50.0 A to the east. Suppose we apply to this wire a magnetic field that produces on it an upward force exactly equal in magnitude to the wire's weight, causing the wire to "levitate." What are the field's...
Homework Statement
Sketch and label the x-ray spectrum for an x-ray tube with copper as its target, operating at an excitation potential of 20kV.Assume that the copper energy levels are K shell=-9000ev,L shell=-1000ev,M shell=-200ev.
Homework Equations
This question has me a bit...
Today there was a question that asked what would reduce copper?
As a multiple choice question, it was narrowed down to Ca and Zn as they were the only ones that would oxidise more readily than copper.
However, as Ca was lower than Zn, I chose that one because it was the "weaker oxidizing...
I am in the process of designing a grounding assembly for a high voltage switch and need to determine what contacts will handle 1200amps. The contacts are U-shaped and a flat copper conductor bar rotates into the U-shaped contact to make the connection. Can anyone point me to a reference or give...
Hi,
I wonder if someone could shed light on my question.
It's kind of related to Fourier Transform and attenuations on signals.
As everyone knows, in the early days, the communication on the local loop was on dial up which was basically analog communication.The digital data in computer...
Please help with the below question: I have given my attempt below!
"A copper sphere of radius 2.000 cm is placed over a hole of radius 1.990 cm in an aluminum plate at 20 deg. C. At what common temperature will the sphere pass through the hole?"
My answer:
((∆T(23* 10-6)(0.01990)-...
I am trying to work out the real component of the wavelength of microwaves in copper. I am given n2=er=-i sigma/eo omega
where n is the refactive index
er is the relative permitivity
eo is the permitivity of free space
i = sqrt(-1)
omega is the frequency of the microwave
sigma is the...
Homework Statement
The Shear modulus for aluminum and copper are 25GPa and 35GPa, respectively. An aluminum and copper pole, both the same length are subjected to the same shear force at the top of each pole, bending each pole a different angle y. Which pole has a higher angle of deflection...
Hello All,
I am trying to do some research to see how many known magnetic effects (related specifically to conductors) have been discovered. So far, I know of the most common one, The Lorentz Force, which is due to the effect of an electromagnetic wave moving across a wire. I am specifically...
Homework Statement
8.0 g of aluminum at 200 C and 22 g of copper are dropped into 55 cm^3 of ethyl alcohol at 15 C. The temperature quickly comes to 28 C. What was the initial temperature of the copper?Homework Equations
The Attempt at a Solution
tried using calorimetry equations, not getting...
This is an interesting piece I am torn about. Copper from brake pads are known to run off into water ways. It is also known in lab experiments that the copper levels found in the water ways can affect salmon. Yet, there is no documentation for this happening in the wild. The state is going...
Homework Statement
A copper wire with cross-sectional area S=2.5 mm^2 is bent to make three sides of a square frame that can pivot about the axis 00' as shown below. The wire is located in a uniform vertical magnetic field B. If upon passing a current I=16 milliAmperes through the wire, the...
The resistivity for thin films can be obtained using Fuchs theory
\rho = \left[1-\left(\frac{3}{2\kappa}\right)(1-p)\int_1^\infty\left(\frac{1}{t^3}-\frac{1}{t^5}\right)\frac{1-\exp(-\kappa t)}{1-p\exp(-\kappa t)}\mathrm{d}t\right]^{-1} \rho_0
where p is the probability that an electron...
Homework Statement
a copper wire of length of length L and cross sectional area A has resistance R. A second copper wire at the same temperature has a length of 2L and a cross sectional area of 1/2 A. what is the resistance of the second copper wire?
Homework Equations
R = pL/A
L =...
Homework Statement
1. The wiring in a house must have low enough resistance so that it does not heat up too much while current is flowing. A particular copper wire needs to carry 20 A of current, and it must not dissipate more than 2 watts of power per meter of length. The resistivity of...
Homework Statement
When a copper cube of side of 2.0 cm is immersed into a perfectly insulated container filled with 1.0 kg of water at 5 degree celcius , the temperature of water rises to 7 degree celcius . Assuming that no heat is lost to the surrounding , calculate the original...
A copper wire is in the form of a cylinder and has a resistance R. it is stretched till its thickness reduces by half of its initial size. Find its new resistance in terms of R.
Homework Statement
a magnet that weighs 2.6 grams is dropped through a 1.53 metre tube. the average time taken for it to go through is 1.59 seconds.
I need to find the strength of the magnetic field and the currentHomework Equations
Fg=mg
B=F/IlsinthetaThe Attempt at a Solution...
Homework Statement
Why does a magnet move slowly in a copper tube, but doesn't in a nonmetal tube?
Homework Equations
Electromagnetic induction (Faraday’s principle) is the production of voltage across a conductor situated in a changing magnetic field or a conductor moving through a...
Homework Statement
The electric dipole moment of a CuSO4 molecule is 3.2 * 10^-32 (i.e. 10 raised to the power of -32)C-m. Find the separation between the copper and sulphate ions.
Homework Equations
Electric deipole moment = 2aq where 2a=separation between the two charges q and -q...
Suppose you wish to fabricate a uniform wire out of 1.0 g of copper (Density of copper is 8.93 x 10^3 kg/m^3). If the wire is to have a resistance of R = .5 ohms, and all the copper is to be used, what will
a) the length and
b) the diameter of this wire?
this has me tottally confuzed...