Unit Definition and 1000 Threads

Homework Statement [/B] Sun Tyrant: 25, 28, 25, 28, 29, 24, 28, 24, 24, 28, 30, 24, 22, 27 Sun Acrid: 29, 31, 29, 26, 28, 22, 25, 29, 29, 27, 28, 23, 26, 29 Laminatekist: 25, 26, 26, 26, 26, 28, 27, 26, 25, 28, 24, 28, 27, 25 This data set shows the number of raisins in each of 14 boxes of...

I would like to reopen a discussion on assertions made by David Mermin such as: “There is no conceivable way to assign such instruction sets to the particles from one run to the next that can account for the fact that in all runs taken together, without regard to how the switches are set, the...

If one atomic mass unit is 1/12 of a C-12 atom, so 1 amu must be; 1 Amu = 1/2 ( Mass of proton + Mass of neutron + Mass of electron ) But the equation gives the answers that 1 amu is 1,6737 10^(-27) kg, which is different than the internet says I am using very sensitive values for the...

This isn't really so much of a specific example from a textbook, I just need to understand how to do this kind of integral and from that I can infer how to do all of the other problems. 1. Homework Statement The current problem I'm having trouble with is: Integral of (5u(t-1)) from T to -T...

please someone explain me the following expression for Cartesian unit vectors expressed by the cylindrical unit vectors: http://web.mit.edu/8.02t/www/materials/modules/ReviewB.pdf at page B-8 line B.2.4 i would like to know which steps led to it. thanks, Chen

Homework Statement Find convolution of x[n] (graph in attachment) and h[n] where h[n] = u[n] Homework EquationsThe Attempt at a Solution - flipped the h[n] to have h[-n] - moved to the left once (h[-1-n]) to align - multiplied h and x and it gives me all zeros Is this correct or I'm missing...

There are three regions: East, West, and Central. Each region has dollars, gallons, and dollars per gallon. There are forecasted numbers as well as actual numbers. East - Forecast - USD50,000; 1,200 gal; USD41.67/gal West - Forecast - USD75,000; 1,700 gal; USD44.12/gal Central - Forecast -...

Homework Statement electric field polarization for a given antenna is expressed as: E_i = (a_x + a_y) E (r, theta, phi) The unit vector along the antenna polarization is found as u_a = 1/Sqrt(2) (a_x + a_y)2. Question Where/how is the 1/Sqrt(2) found to resolve those other 2 vectors into a...

Homework Statement During the Cold War the US and the former Soviet Union built up enormous arsenals of nuclear weapons. Although the exact amounts are not known, particularly for the USSR, the stockpile of the US arsenal alone is knowledgeably estimated to have a total destructive power of...

Homework Statement So the full problem reads: A vector F has the same magnitude and direction at all points in space. Choose the z-axis parallel to F. Then , in Cartesian coordinates, \vec{F}=F\hat{z}, where \hat{z} is the unit vector in the z direction. Express \vec{F} in spherical...

Homework Statement A and B are two unit vectors in the x-y plane. A = <cos(a), sin(a)> B = <cos(b), sin(b)> I need to derive the trig identity: sin(a-b) = sin(a) cos(b) - sin(b) cos (a) I'm told to do it using the properties of the cross product A x B Homework Equations A x B =...

Hi guys I have a problem - I can´t seem to figure out the correct unit and name (like power or work). In the attached file, the blue graph is showing the applied pressure/force on a sensor vs. time. The red area is the area below the blue graph. I have two of these sensors, and I would...

1. I'll just post the entire question list for this chapter in image format. http://imgur.com/retjkzJ1. i) The amplitude is the measurement of the wave from the equilibrium point to the trough or crest of a wave. The wavelength is the measurement of two successive points of a wave. ii)...

Hi, I am wondering as to how to define the boundary condition for a shape in a unit cell. Just imagine that the shape is the hole for the unit cell. Hence, for a constant thickness on the untextured boundary, thickness is, let's say C, then for the circle, it's C+depth. For example for...

hi there, I am trying to prove the following inequality: let z\in \mathbb{D} then \left| \frac{z}{\lambda} +1-\frac{1}{\lambda}\right|<1 if and only if \lambda\geq1. The direction if \lambda>1 is pretty easy, but I am wondering about the other direction. Thanks in advance

After specifying the primitive vectors of a structure namely (a,b,c) in Wien2k, one has to specify locations of atoms in unit cell.There are three components X,Y,Z which determine the atom location. I want to know whether "X,Y,Z components" are corresponding to vectors a,b,c or they are...

The Riemann curvature of a unit sphere is sine-squared theta, where theta is the usual azimuthal angle in spherical co-ordinates, and this is shown in many textbooks. But since a sphere is completely specified by its radius, then as far as I can see its curvature should be a function of its...

In the Feynman Lectures on Physics chapter 28, Feynman explains the radiation equation $$\vec{E}=\frac{-q}{4\pi\epsilon_0 c^2}\, \frac{d^2\hat{e}_{r'}}{dt^2}$$ The fact that the transverse component varies as ##\frac{1}{r}## seems fairly obvious to me since what matters is just the angle...

I think this is a textbook-style question, if I am wrong, please redirect me to the forum section where I should have posted this. This is my first time here, so I am sorry if I am messing it up. Homework Statement We have an n-dimensional vector \vec{r} with a constant length \|\vec{r}\|=1...

dear friends, I have always wonder: is there a smallest unit for time and matter? or in other words, can we continuesly divide time and matter into smaller pieces non-stop? ive had this question since young when I imagined myself cutting a piece of cheese. I just can't help stop cutting it and...

Hello everyone. I am a Hungarian born Australian theoretical/applied physicist. This is my first post on the forums. I am aware that silicon carbide crystal occurs in many different crystalline forms. I was wondering if someone here could please point me to a source that catalogs the...

Let's say i spin an object around me with a greate velocity. At some point, i leave that object and it moves in a straight direction with a velocity of 0.9c. If so what was its velocity while it was revolving around me? How do i experes it?

Homework Statement For the equations: y1 = 1-x^2 y2 = x^2 -1 find the unit tangent vectors to each curve at their point of intersection. Homework Equations d/dx (y1) = -2x d/dx (y2) = 2x The Attempt at a Solution After solving for points of intersection between the...

During an interaction on TeX.SE, egreg there posted some truly awesome code for doing unit vectors in $\LaTeX$: \usepackage{newtxtext} \usepackage{newtxmath} \usepackage{amsmath} \usepackage{bm} \newcommand{\uveci}{{\bm{\hat{\textnormal{\bfseries\i}}}}}...

Homework Statement This is almost exactly the same problem as my earlier post, however different equation and point. Find the unit vector parallel to the graph f(x) = tan(x) and the point (pi/4 , 1) , and the unit vector perpendicular to the graph and point (pi/4 , 1 ). Homework...

Homework Statement Find the unit vector normal to the function f(x) = -3x^2 + 5 and the point (1,2) and find a unit vector parallel, using f(x) and the point (1,2). Homework Equations How do I find the slope here? I attempted to just use the point (0,5), and then the given point...

I need to convert 12.5 MPa·mm1/2 into MPa.m1/2. I am unsure on how to do this, my two guesses are as follows: 1. (12.5) / ( 1 / 10001/2) = 395.28 MPa.m1/2 2. (12.5) / (12.5 / 10001/2) = 31.62 MPa.m1/2 Is either of those correct? Thanks!

I have a pressure vessel of volume V= 1 m^3 . The atmospheric pressure Patm = 101 kPa and Tatm = 22 C. I slowly pump liquid water into the pressure vessel until the internal pressure reaches P1 = 15 MPa. Also, the process is isothermal because the water was pumped in slowly and heat is exchange...

i came to this topic and they said Duf(x) = ||gradient vector|| * ||U|| * cos 0 if ||U|| were not a unit vector it would give different rate of change of f in any direction what would happens if used ||U|| = 10 ?

I am setting up a numerical simulation from a 2D discretization of the heat equation in cylindrical coordinates. my spatial variables are radius (r), height (z), and azimuth (ø). The assumption is that there is no gradient along the azimuth direction (if temperature is T then dT/dø = 0)...

In many, many articles about the SQUID magnetometer, I see people referring to the sensitivity of the magnetometer in units of EMU, as in this article: http://iopscience.iop.org/0268-1242/26/6/064006 or this http://link.springer.com/article/10.1007%2FBF02570388 Could someone please explain...

While investigating more about complex numbers today I ran across the 2x2 matrix representation of a complex number, and I was really fascinated. You can read what I read here. As I understand it, you write z in its binomial form but instead of "1" you use the identity matrix, I, and for i...

Hey there, This isn't a homework question, it's for deeper understanding. So I'm learning about unit normal/tangent vectors and the curvature of a curve. I have a few questions/points. 1) So my book states that we can express acceleration as a linear combination of the acceleration in the...

I want to show that the modulus of the automorphism \frac{a-z}{1-\overline{a}z} is strictly bounded by 1 in the unit disc. Applying Schwarz lemma gives the result immediately. But I am looking for a straight forward proof for that. Thanks in advance

As an Electrical Engineer, I am employed in a Power company. In this company, they want to create a unit for Protection which cover for both the Generation Department and the Transmission & Distribution Deparment. This is my 3rd month in the company. I was advised to make a plan on how to...

Hello. Electrical conductivity is written as \frac{n_{e}e^{2}}{m_{e}\nu_{ei}} where n_{e}, e, m_{e} and \nu_{ei} are for electron density, charge, mass and electron-ion collision frequency. According to Wikipedea, http://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity Unit...

Hello. In CGS unit electron thermal conductivity for plasma is expressed as \frac{n_{e}T_{e}}{m_{e}\upsilon_{e}}\Gamma_{1} [1] where \Gamma_{1} is the dimensionless transport coefficient. [2] You can also find similar expression in...

I never see before a formula for a eigenvector, however, given a generic matrix (http://www.wolframalpha.com/input/?i={{A%2C+B}%2C+{C%2C+D}}) the wolfram is able of find the eigenvectors... So, exist a formula for the unit eigenvectors?

Homework Statement The period of Mars is 1.881 years. When Mars is opposite the Sun in the sky, its position with respect to the background of fixed stars is measured at sunset and again at sunrise. The effective baseline between the two positions is 11,700 km and the change in position on the...

I have some noisy data (x-y coordinates) containing two distinct clusters of data. Each cluster is centred at an unknown point on the unit circle. How can I estimate these two points (green points in the diagram)? We can assume the noise is Gaussian and noise power is equal in x and y...

I think I mostly understand how this works, and it makes intuitive sense. However, I'm a little bit confused by one step in the proving of this. On the second page of the attached PDF, there is this statement: x' + kx = (r/k + c2)δ(t) ... (followed by the cases of t<0 and t>0 What comes...

If Newton is unit for measure force, meter is unit for measure length and radian is unit for measure angle, so, bel is unit for measure which physical(/mathematical) quantity?

Hi all, I am having a homework problem that is statement really bothers me and I think it might be a typo. It goes in the following: Homework Statement A is a short life unstable state and it is in equilibrium with B and C. A\LeftrightarrowB A\LeftrightarrowC The equilibrium rate constants...

EXAMPLE QUESTION: Calculate the mass per unit length of the wire, μ, given by μ = g /(2fG)^2 where g = 9.81 N kg–1 and f = 50 Hz. For example here is it mass per unit length and so would it be kg/m? It kg/m the same as kgm^-1. But then how do I identify the units like kgm^-2 like how...

I am bit confused on the units when you convert acceleration to displacement. The accelerometer data is in bits. I can convert this to gs or milli gs. When integrating, this will get multiplied by millisecs. What will the displacement unit be in?

Here is a example 1.3 from analytical dynamics of Haim Baruh. a particle moves on a path on the xy plane defined by the curve y=3*x^2 , where x varies with the relation x= sin(a). find the radius of curvature of the path and unit vectors in the normal and tangential directions when a=pi/6...

Homework Statement Effective Power generation of the plant is 5.43*10^{7}W but it will required 9*10^{16}J to be created. Essentially the break-even will after solving equation Energy required/Power Generated however I get results of almost 50 years. Would this be correct...

1. estimate the fermi energy for lithium... the crystal structure of lithium is a bcc with a unit cell size of 3.5*10^-10 m [b]i need n, which equals N / V. if i divide by per atom, then i get (N/atom) / (V/atom) = valance / (V/atom). my question is how to get the volume per atom...

Homework Statement I am trying to calculate the flux for the octant of a sphere, and I am trying to figure out how the mathematics, dot products, and dA works in the integral. I already did the quadrant for \hat{θ} where θ= π/2 (the bottom quadrant) and I did the left quadrant where \hat{n}...

In my textbook, it states that given q1 and q2 where both charges are positive and of equal magnitude, the unit vector r-hat always points away from q1. Why is this so? What if both charges are of opposite charge? Does r-hat still points away?