Unit Definition and 1000 Threads

I cannot get the answer of the problem as in the book but the book usually right. I did it in 2 totally different ways and I still get my own answer. Can anyone help me double check? This is to find u(r,\theta,\phi) given: \nabla^2 u(r,\theta,\phi) = -k u(r,\theta,\phi) = f(r)=1 \hbox {...

I was just trying to get my head around a point that was a little obscure, when I realized that part of the problem was that in thinking of momentum I hadn't got a name to hang on the unit. Unlike energy, where you just think so-many-Joules or Force (ditto-Newtons), you get stuck with this...

The ampere is that constant current which , if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 metre apart in vacuum, would produce between these conductors a force equal to 2 × 10 ^{–7} Newton per...

Homework Statement Find the maximum of |ez| on the closed unit disc. Homework Equations |ez| is the modulus of ez z belongs to complex plane Maximum Madulus Theorem - Let G be a bounded open set in complex plane and suppose f is a continuous function on G closure which is analytic in...

Do I have memorize the entire Unit circle ?? Homework Statement I am currently takin a trig class and I was a bit daunted by the Unit Circle and all its special angles. My question is... Do I haveto memorize the entire Unit Circle and its angles?? Will it be given to me during exams(as...

Homework Statement For the scalar field f(x, y, z) = x2 − y2 − z find gradf and normal unit vector to a surface f(x, y, z) = 0 at the point (1, 1, 0). Homework Equations The Attempt at a Solution I calculated gradf= 2xi -2yj -k at (1,1,0) this is = 2i -2y -k normal unit...

The unit normal vector N of a given curve is equal to the first derivative with respect to t of the unit tangent vector T'(t)divided by the norm of T'(t) (For a parametric vector equation of parameter t.) I realize this works because T(t) is orthogonal to T'(t), but I don't understand why the...

How do you derive the hypervolume/hypersurface of the unit ball in n dimensions? I thought it'd be trivial but oh well. I'm guessing switch to n-D spherical coordinates? Is there an argument which doesn't involve explicitly calculating too many things? :x

So I'm trying to find out what the procedure is to convert a cartesian unit vector to a cylindrical unit vector. Any thoughts?

Q.The unit cube length of LiCl (NaCl structure) is 5.14 amstrong . Assuming anion-anion contact, calculate the ionic radius for chloride ion. How to assume anion-anion contact ? Can anyone help with a 3D figure?

What is the average radius for a unit cell, for example, for Na? Is it the average of the ionic radii for the different coordination numbers (weighting each coordination number the same)? Or would it be the covalent radii or something else?

Homework Statement Find all solutions to the equation below such that -180° \leq x \leq 90° 2sin2x + sinx = 0Homework Equations The Attempt at a Solution 2sin2x + sinx = 0 sinx[2sinx + 1] = 0 sin x = 0 sinx= -1/2 x = {0° + 360°n {-180° + 360°n n\epsilonI

Let M be the surface defined by z=x2+3xy-5y2. Find a unit normal vector field U defined on a neighborhood of p on M. First, I reparameterized the equation for the surface to get x(u,v)=(u,v,u2+3xy-5y2). Next I found two tangent vectors xu(u,v)=(1,0,2u+3v) and xv=(0,1,3u-10v). The next step is...

Homework Statement Find the unit normal to the plane 3x + 5y - z = 2. What is the distance of the plane from the origin. Homework Equations The Attempt at a Solution The normal vector in component form --> (3, 5, -1) Magnitude of the normal vector --> √35. Divide the normal vector by its...

Homework Statement One bottle of magnum contains a volume of 1.5litres. 1 bottle of boream contains a volume of 0.792 us gallons. How many bottles of magnum will fit in 1 bottle of boream? Homework Equations litres to galons galons to litres The Attempt at a Solution Uh...i've...

Homework Statement The person fell from the plane 6 miles and survived the fall. What is the distance the person fell in metres? Homework Equations 1m=3.281ft 1mi=5280ft 1ft=0.3048m The Attempt at a Solution I figured if 1 mi = 5280ft then 6 miles must be : 6(5280ft)=31...

energy from electron passing between 2 electrodes, and calc. the freq of the elec. Homework Statement Part 1: The difference in potential between the cathode and anode of a spark plug is 17800 V. What energy does the electron give up as it passes between the electrodes? Answer in units...

Is there such a concept in information theory? I.e. Something as complex as language can be reduced to 1's and 0's. Is binary the fundamental unit of information?

Hello everyone, i have my HTPC inside cupboard, thus when stressed it overheats. on top of the cupboard i have some slits, and i wanted to build a cooling unit to circulate the air inside. i thought of using there fans...

Homework Statement Find unit normal vector to the surface z = 2xy at (2,1,4) Homework Equations - The Attempt at a Solution fx = 2y fx(2,1,4)=2 fy = 2x fy = 4 = (2,4,-1) is this correct? and in the right format?

Homework Statement a) Find the intervals of unit length on which f(x) = 2x^{4}-8x^{3}+24x-17 has it's zeros. b) For each of the following starting intervals, tell which of the zeros of f(x) will be found by the bisection method associated with the proof of Bolzano's THeorem. (Label the zeros...

Why do we have an imaginary number? I don't see it's usefulness. Why dos it matter if we can make up a number that satisfies this equation (\ x^{2}+1=0 )? It must have real world applications that I'm unaware of.

Homework Statement Let l∞ be the space of bounded sequences of real numbers, endowed with the norm ∥x∥∞ = supn∈N |xn | , where x = (xn )n∈N . Prove that the closed unit ball of l∞ , B(0, 1) = {x ∈ l∞ ; ∥x∥∞ ≤ 1} , is not compact. Homework Equations The Attempt at a Solution I'm...

I'm calculating the band-to-band probability using the WKB approximation given by T=exp(-4*lamda*sqrt(2*m*Eg^1.5)/(3*q*hbar*(deltaPhi+Eg))). I am wondering which unit of the plank constant is used here? The one in J-s which is 6.62e-34 or in eV-s which is 4.13e-15? However, the former one...

What quantity has the same numerical value as the gravitational field strength, but is expressed in a different unit? g= 9.8 N/kg i can't think of anything else that's 9.8 besides g

Homework Statement Find the Laplace transform of cos(t)h(t) if the LT of h(t) (unit step) is 1/s Homework Equations --- The Attempt at a Solution Since the unit step isn't shifting anything anywhere, can I just treat it as 1? Seems too simple, haha. Any ideas? thanks.

Homework Statement Linear Algebra: For all the unit vectors u=[x,y,z]^T in R^3. Find the one for which the sum x+8y+2z is minimal. (u is a 3 x 1 vector) Homework Equations The Attempt at a Solution I tried working this with the least squares method...it wasn't right. I am...

Given two vectors \vec{A} = - 2.00 \hat{ i } + 3.00 \hat{ j } + 4.00 \hat{k} and \vec{B} = 3.00 \hat{ i } + 1.00 \hat{ j } - 3.00 \hat{k}. Obtain a unit vector perpendicular to these two vectors. Express your answer as a unit vector N_unit in the form N_x, N_y, N_z where the x, y, and z...

Why is the number of electrons per unit volume , n fixed in a conductor regardless of the temperature while its not in semiconductors ??

Homework Statement In the open unit disk D = {(x,y)|x2 + y2 < 1} give a forumla for: (a) \frac{\partial \sum ^{inf}_{n=0} (xy) ^{n}}{\partial x} (b) \frac{\partial (e^{x+y} \int ^{y}_{x} e^{-t} dt)}{\partial y} Homework Equations The Attempt at a Solution...

"a silicon cristal is doped with 1000000000000000000 cm^{-3} atoms of antimon" how does cm^{-3} represents a number of atom why not just say "a silicon cristal is doped with 1000000000000000000 atoms of antimon"

I am currently working on an implementation of a Symbolic Algebra system similar to existing products. In this system, I would like to be able to display the exact symbolic values of trigonometric functions for any given angle in radians. ex: sin(PI/6) = "1/2" My problem stems from...

Homework Statement Two wires have current both running in the positive x direction as shown in the diagram with I1 = 13.9 amps and I2 = 4.5 amps. They are separated by a distance of d = 4.7 meters. A third wire with I3 = 10 amps is placed somewhere between the two wires with current running...

I am trying to come up with a way to utilize the heat that is being dissipated by a huge freezer's condensing unit. Currently the heat is being dumped permanently in the plenum. One of the possibilities that a leaning for the most is using the heat that is being dissipated during the heating...

Homework Statement A golfer takes three putts to get the ball into the hole of a level putting green. The first putt displaces the ball 2.5 m North, the second 4.8 m South-East and the third 5.7 m South-West. Express each of these three displacements in unit vector notation where i is a...

Hello everybody! I found a great resource which helps me a lot solving unit conversions. I could find more than 5000 units and 70000+ unit conversions and a lot of discussions on important unit conversions. Here is the link http://www.converter.pk

Hi everyone. I wasn't really sure where to put this thread so I stuck it here, which seems the closest fit. Anyway I've been thinking about this for too long: what characterises the unit ball of a norm? Let's be specific: consider a finite-dimensional vector space, which may as well be...

Homework Statement S = { z | |Im(z)| < 5 }, z is a complex number Homework Equations I am trying to generate a mobius transformation w = f(z) such that it will map S onto a unit disc but I keep running into problems and contradictions. I think there is a big mistake in my attempt but I...

In my teacher gave us homework on electricity. One of the questions ask "what is the potential energy of the pair of charges? Answer in the units of V." Is that an error, or is there a way to convert Joules to Volts?

I was given the question, If u=ai+2j+4k and v=3i+bj+k, calculate a and b in a textbook from school (revision for a test). Any thoughts?

Is there a physical unit related to the Green's function of the wave equation? In particular, let \nabla^2 P -\frac{1}{c^2}\frac{\partial^2 P}{\partial t^2} = f(t) where P is pressure in Pa. Since the Green's function solves the PDE when f(t) is the delta function, the Green's function G...

Homework Statement r(t) = <cosh(t), -sinh(t), t> not given a value for t. Homework Equations r'(t) N(t) The Attempt at a Solution T = r'(t)/distance[r'(t)] how do you find unit tangent vector and the unit normal vector without being given a value for t? r'(t) =...

I am reading a paper on irradiation damage to semiconductor devices, the author mentioned a dose unit Mrad(Si). Can anyone tell me what it is? Thank you very much.

Homework Statement Im given two vectors and I am told to find theyre unit normal vector. Homework Equations a x b The Attempt at a Solution I used the cross product of the 2 vectors to find the normal vector, however, it came out to be i + j + k. My question is, is this already a unit vector...

Unit for Molar Mass(M)?? Homework Statement What's the unit for Molar mass? Is it different in CHemistry and Physics? Homework Equations PV=nRT The Attempt at a Solution In Chemistry class(last year) I think I used (g/mol). But in Physics, my teacher says it's (kg/mol). What is...

Laplace Transform of unit step function HELP! Homework Statement f(t)= e^t on 0<=t<1 . . . . t on 1<=t<2 . . . . sin(t) on 2<=t<infinity Homework Equations Unit Step Function The Attempt at a Solution Here is my attempt at a solution...

Anyone who can tell me the corelation between Hartridge Smoke Unit (HSU) and FILTER SMOKE NUMBER(FSN) as I have the two systems giving one in HSU and the other in FSN.I would like to compare the result given by the two SYSTEM

Hi, i have a problem with integration a function with a unit step function. Homework Statement Given, Refer to the image, i dun understand is that u(t) is equal to 1 from a definite integration from -\infty to \infty since u(t)=1 from -\infty to 0 and u(t)=0 from 0 to \infty...

Homework Statement The coaxial cable from a television or other device has an inner conductor with diameter of 1 mm and the shield of diameter 5 mm. Assume a plausible value for the dielectric constant (3 ≤ κ ≤ 5) of the dielectric separating the two conductors and calculate the capacitance...

Homework Statement http://img22.imageshack.us/img22/1254/10031833.jpg Homework Equations The Attempt at a Solution My attempt was based on the idea that both triangles formed by the vector components (x component, y component, and the hypotenuse which is the magnitude of the...