Relationship Definition and 986 Threads

Homework Statement If U is a 2 x 2 unitary matrix with detU=1. Show that |TrU|≤2. Write down the explicit form ofU when TrU=±2 Homework Equations Not aware of any particular equations other than the definition of the determinant and trace. The Attempt at a Solution I have...

(Part of) The proof/logic of Bell's theorem goes thus: With the measurements oriented at intermediate angles between these basic cases, the existence of local hidden variables would imply a linear variation in the correlation. However, according to quantum mechanical theory, the correlation...

Homework Statement Which of the following statements about friction is correct? I. Kinetic friction always decreases the mechanical energy of a system. II. The static friction force cannot change the mechanical energy of a system. III. The force of friction always points in the direction...

A spring is at the bottom of a frictionless incline. When a box of mass M compresses the spring distance x and is released from rest, the box slides distance d up the incline (measured from where the box is at rest). a) Suppose a box of mass 2M is used to compress the spring distance x,and is...

I am trying to make a .4 Tesla AC (50Hz) magnetic coil. Originally I used ID-38MM, OD-155MM & Length of Solenoid 50MM. Using 3.5MM X 1.5MM wire 380 Turns. I get 0.27 Tesla at 75Amp. but the wire allows me to work only for around 5 Min with Forced air cooling. I do not know the relationship how...

Is "space" a thing or a relationship between existents? When I think of "space", I think of the distance between things rather than "space" being a thing like me or a planet or some other existent. If "space" is a a thing and not "nothing" can it be described like any other thing that exist...

Homework Statement What is the relationship between the weight of the hanging washers and the force acting on the stopper by the string? Here is the diagram provided by the book: http://www.goodreads.com/photo/user/5034346-kylaia-formerly-known-as-klymene?photo=454140 It also says to...

Is there some sort of relationship between the differential dx and the differential operator which means to take the derivative d/dx if x is a dependent variable? My prof said that dx * d/dx = 1 but that doesn't seem to work out in the case I'm looking at, so I must be missing something.

Hi, i was doing practice questions for an exam in a couple of weeks and i had his question: An object is dropped from height hand strikes the ground at time t, if the object is dropped from a height of 2h, which of the following represents the time it will take to strike the ground? A. t B...

Homework Statement The four points shown in the attached picture are near a positively charged rod (shaded circle). Points W and Y are equidistant from the rod, as are points X and Z. A charged particle with mass 3.0 x 10^-8 kg is released from rest at point W and later observed to pass...

Why is it that atoms must have 8 valence electrons in order to be stable? Aren't electrons most stable when the orbital is completely filled? Helium's electron configuration is 1s^2, Neon's is 1s^2 2s^2 2p^6, etc. All the noble gases, except for helium, have the p orbital filled. I'm...

In this diagram: http://img692.imageshack.us/img692/3012/tqmo.png what exactly are they trying to convey as in, what is the relationship between TQM, QA, QS and QC? Does each outer circle encapsulate all the inner circles? For example, it QA a part of TQM, while QS is a part of QA etc.? I...

Dear Physics Forum, Is there any model where the electron and quark share a fundamental relationship, maybe in some string theory? I ask because it seems too much of a coincidence that two completely independent particles would have a simple charge relationship of 1/3:1 . Thanks, Mark

Homework Statement Relate the frequency of a harmonic oscillator (spring) to that of a simple harmonic oscillator (pendulum) Show all derivations. Homework Equations pendulum: f=(1/(2∏))√(g/L) The Attempt at a Solution Not exactly sure how to go about this...is it saying...

First of all sorry if this is the wrong section! For a physics assignment, I am given a graph of which I am to gather data from. Graph 1: In an experiment to investigate how the celsius temperature, T, affects the volume, V, of an enclosed sample of air at a constant pressure, a students...

What is the relationship between the equation E^2 - p^2c^2 = m^2c^4 and E = mc^2?

Problem : A conducting metal balloon of Radius ' R ', essentially of negligible mass is charged with charge ' Q '. It has to carry a payload of mass ' M '. Find how the charge ' Q ' depends on the mass M and the Intrinsic Energy ' W ' of the balloon. Attempt: We have P_{atm} =...

Two speakers A and B are separated by 1 meter, the point P is 4 m away from speaker B. If P is a person for what frequency does he hear that the intensity have a minimum?. (The listener hear that the sound intensity reduces and increases).I don't know the distance from P to B. (They form a...

Is there a relationship (or equation) between a charge carrier's drift velocity through a conducting material and that material's resistance? I'm trying to reconcile the idea that drift speeds are bigger when cross sections are smaller and the idea that resistance is bigger when cross sections...

Homework Statement A mass attached to a spring which is mounted on a turntable. If you wanted to double the angular velocity, but keep the radius of the circle the same, by how much would you change the spring constant? Homework Equations \omega = \frac{v}{r} The Attempt at...

Homework Statement do you notice a relationship between the plane and directions of the same miller index? what is it? Homework Equations I've done planes and directions (111), [111], (112), and [112] The Attempt at a Solution I believe the direction is normal to the plane on first...

Homework Statement When the voltage across the two plates of a capacitor is increased then: *a. the charge will increase b. the charge will decrease c. the capacitance will increase d. the capacitance will decrease Homework Equations CV=Q The Attempt at a Solution...

Why is the number of charge carriers per unit volume is inversely proportional to resistance?If there is more charges carrier, it doesn't increase the collision between free electron which causes in increase of resistance?sorry for my unclear concept of Electricity circuit.I hope there will be...

can temperature be changed without changing pressure as well as number of molecules for an ideal gas?

Homework Statement The table gives a firm’s monthly profits for their first few months of business. The numbers are rounded to the nearest £100. Number of months after start up (x) 1 2 3 4 5 6 Profit for this month (£y) 500 800 1200 1900 3000 4800 The firm’s profits, £y, for the...

Homework Statement Homework Equations Sum of roots taken one at a time is -b/a Sum of roots taken two at a time is c/a three at a time is -d/a four at a time is e/a The Attempt at a Solution I did part one by solving the two equations...

I'm doing a solar cell characterization project. But due to some fault in my solar simulator(I'm getting different results from another set up), I'm now figuring a way to check the intensity of light shone by my simulator on cell. I'm trying to obtain it from the corrected data of my cell (Isc...

If our eyes can perceive light and light is energy then why is energy defined as an indirectly observed quantity?

Let's say I have a wave with 3 nodes and 2 antinodes if I doubled the frequency applied to the wave how many nodes and antinodes would my new wave have?

A huge common misconception about brain function is that function can be localized to "very" specific locations. However, reductionism falls apart when speaking about emergent phenomenon such as higher order brain functions (e.g. feeling of knowing, consciousness, visio-spatial processing). Just...

What is the the relationship between the specific heat capacity and power (e/t) required to raise the objects temperature? Of course the energy required increases, but does the time it takes change also?

I live in the DC metro area and we recently had snow that lasted all day (none stuck to the roads, booo). But I didnt understand that it was still snowing at well above freezing. I have a digital thermometer outside of my window and it read ~41 degrees F at its highest and never dropped below 32...

First consider the following definitions from Baby Rudin: Interval: A set of real numbers of the form [a,b] where for all x \in [a,b] we have a \le x \le b. K-Cell: A set of k-dimensional vectors of the form x = (x_1, ...,x_k) where for each x_j we have a_j \le x_j \le b_j for each j from...

Greetings! I'm new coming to this page but I have a question whose answer goes beyond my understanding of physics...really,even the question goes beyond my understanding but I feel comfortable enough to ask the question, just forgive me if I use the wrong wording... I've read and heard about...

εHi, Based on that hoary schematic cube representation in 3D for stress-strain relationship. Stress tensor {σxx, σyy, σzz, σxy, σyz, σzx} and strain tensors {εxx, εyy, εzz, εxy, εyz, εzx} can be written interchangably. Let's suppose that σzz=σzx=σzy=0 then the reamining terms are written...

Okay, so I have a sound wave (a visual representation). From this I can see the amplitude of the wave, However, I need to know what the sound power or the sound pressure level. Could someone please give me a formula that could help? Thanks

A sound is measured to have a decibel level of 30dB. If the intensity is decreased by a factor of 2 by how much does the intensity level change? β=10 x log(I/Io) β=Intensity level I=intensity of the object Io= Threshold of hearing(human) If the I increase so the β increase If so the...

hi, i have seen on another topic here that the refractive index equals the square root of the dielectric constant. from datasheet values we have... water refractive index = 1.333 dielectric constant = 80.1 Without even doing the calculation its obvious that the square root of 80.1 is not...

So I'm trying to understand how the Higgs field and Higgs boson are different from the EM field and the photon. Firstly how I understand the photon is that It is the quanta of energy that an electromagnetic field oscillating at a certain frequency can give to some other system. The photon is the...

Hi, I am a postgraduate environmental science student (NOT a mathematician!) struggling through some necessary maths. Any help with the following (which I suspect will be relatively straight foward) would be very much appreciated. Please ask questions if I have not made myself clear. Homework...

I've become rather curious, as of late, about the realm of complex logarthims; more specifially logarithms in the form log(z) where z is any negative number. Excuse any ignorance on my part, as I'm only in Precalculus, but I was just curious to see how Euler's formula is related to complex...

Homework Statement So, let's say a car is rolling down a ramp. I have to maximize its acceleration, but I am confused about some things. I think that if I increase the car's mass, then it will have more momentum and roll down the ramp faster. But according to Newton's First Law of Motion, an...

Hello everyone, Sorry if this is in the wrong sub-forum, I wasn't sure exactly where to place it. I was wondering if there is an orthogonality relationship for the Legendre polynomials P^{0}_{n}(x) that have been converted to cylindrical coordinates from spherical coordinates, similar to...

Homework Statement Consider a 4 x 4 matrix A = B C 0 D where B, C, and D are 2 x 2 matrices. What is the relationship between the eigenvalues of A, B, C, and D? The Attempt at a Solution I suppose you can write A as: b1 b2 c1 c2 b3 b4 c3 c4 0 0 d1 d2 0 0 d3...

Homework Statement The motion of a particle is expressed by a=42-12x2 where a is in m/s2 and X is in m, with the initial condition: v=0 when x=0 and t=0 Determine v when X=6 Determine X when v becomes 0 again Homework Equations I tried using a=dv/dt so i took the anti derivative of a...

Homework Statement I am in the process of studying integration and finding the areas under curves. So far, I know of two methods of finding the area under a curve: the limit method and the direct integral method. Could someone explain the relationship between these two methods? Homework...

"Barrel of Fun" Carnival Ride, and the relationship between Friction and ω Homework Statement A ”Barrel of Fun” consists of a large vertical cylinder that spins about its axis fast enough so that any person inside will be held against the wall. Assume: At an angular speed ω1, an upward...

Hi, I'm taking a thermodynamics class and I'm stuck on how work relates to enthalpy and internal energy. Does work done by a system equal change in internal energy, change in enthalpy or does it depend on the situation? The question I'm stuck on asks for the work produced by a steam turbine...

is there a gas which its volume increases nonlinearly with decrease in pressure?

If we're working in R^n and we consider the elements of a basis for R^n to be the column vectors of an nxn invertible matrix B, then what is the relationship between B and the matrix whose row vectors represent elements of the corresponding dual basis for R^n*? My guess, which Wikipedia helped...