Standard Definition and 1000 Threads

  1. D

    Carbon Steel Pipes to API 5L Grade B Standard Weight

    Greetings! This is for a Chilled water piping project (1000mm dia max). We are procuring pipes from SEAH Korea, from 250mm to 1000mm. And for calculations for support, load, thrust, etc, i need the following details for these pipes. 1. Coefficient of Linear Expansion 2. Longitudinal Elastic...
  2. P

    What is the Calculation for Mean and Standard Deviation with Grouped Data?

    Homework Statement For this set of data find the mean and standard deviation Temp...# of days 90-94...1 85-89...3 80-84...6 75-79...12 70-74...7 65-69...1 2. The attempt at a solution I don't know how to find the mean or standard deviation when the data is divided into...
  3. Z

    How Do You Calculate Standard Enthalpy of Reaction Using Hess's Law?

    this is my question , i just don't know how to get the standard enthaply of reaction of this problem iam sure its easy, but i just don't get it, any help is welcome 14. Given the reactions (1) and (2) below, determine (a) ΔrH and ΔrU for reaction (3), (b) ΔrH for both HBr(g) and H2O(g)...
  4. L

    Standard Deviation of basketball player height

    Homework Statement The mean height of players in a basketball competition is 184 cm. If the standard deviation is 5 cm, what percentage of them are likely to be: a) taller than 189 cm b) taller than 179 cm c) between 174 cm and 199 cm d) over 199 cm cm tall? Homework Equations...
  5. Loren Booda

    Do large dams have a standard design?

    Do large dams have a standard design, like that of horizontal and vertical curvatures (such as width vs. depth)?
  6. B

    Standard Derivation: What Makes it Standard?

    standard derivation?? I read in a paper that the "light clock" approach is a standard derivation of the time dilation formula. Please let me know when do we consider that a derivation is a standard one?
  7. H

    Will Detection Of Higgs Boson Complete Standard Model?

    We are pinning high hopes on LHC experiment. One of the expected results of the experiment is detection of Higgs Boson that would complete the standard model. In fact, discovery of Higgs Boson would complicate the theoretical issues because then we will need to find out.. a. origin of Higgs...
  8. N

    Fluid Dynamics standard reference

    Hi. What's a standard reference for physicsts concerning the topic of fluid dynamics or computational FD.
  9. G

    Calculate the potential (voltage) of a standard cell

    Calculate the potential (voltage) of a standard cell with these half-cell reactions: Ni(s) -----> Ni2+ + 2 e- 2 e- + Cl2(g) -----> 2 Cl- :cry:
  10. N

    Java Comparing Python and Java: Performance & Standard Libs

    Any one have any opinions on the differences between these two language (and their closeness to C)... chroot posted about python being almost as complete as java interms of standard libs. I attended a presentation which seemed to verify that claim though you have to download some of the added...
  11. D

    Any Standard Notation for Multiple Coordinate Systems?

    Homework Statement Given variables in one coordinate system, give the notation used to refer to the variables in another system. The known variable is x Homework Equations The transformation is an arbitrary one. My question has to do with notation and not mathematical procedures...
  12. C

    How Do You Calculate Trigonometric Ratios for Angles in Standard Position?

    Homework Statement 1) If the point (-4, 2) lies on the terminal arm of an angle θ in standard position, determine the exact value of csc θ. 2) If sec θ = -5/3 and angle θ terminates in quadrant III, which point must be on the terminal side of θ? 3) If cos θ = 5/13, where θ is in quadrant VI...
  13. D

    Standard Deviation: Formula (8) Approximation Explained

    Hi all. If I have a function V(x1,x2,x3,x4) and I want to calculate it's standard deviation when x1,x2,x3,x4 are standard normal and their variances are small, then formula (8) on this page http://www.devicelink.com/mem/archive/99/09/003.html" is an approximation to the standard deviation...
  14. E

    Lerning the Standard Model and some question about QM

    Hi I used the last few month two make me familiar with quantum mechanics and read two books. The Feynman lectures on physics and Principles of Quantum Mechanics (R. Shanker). I think I have no problems with the bra-ket notation and solving the Schroedinger equation for some simple particle...
  15. A

    Standard Deviation of Sets X & Y: s_{XY}=s_{X}\overline{Y}+s_{Y}\overline{X}?

    For sets X and Y, is it true that s_{XY}=s_{X}\overline{Y}+s_{Y}\overline{X}, where s represents the standard deviation and XY is the set containing x_{i}y_{i}?
  16. happyg1

    Need Help: Wreath Products & Standard Wreath Products

    Homework Statement Hello, My book has all of 1 page about wreath products and standard wreath products. I'm really lost on this topic and I have 4 homework problems using it. Does anyone know where I could find a little more info on the topic? Homework Equations The Attempt at a...
  17. F

    Chemistry - Quick question about standard reductions of half-cells

    my teacher says that if you add acid to the solution then you don't use the H2) half reaction with the (10-7 M), but that you still do if you add a base. Is this true?
  18. J

    Maximun bps rate on an ITU channel over standard single mode fiber

    I have to find the maximun bps that it can be reach using a point-to-point link of 40 km long of optic fiber. I use an ITU normalized channel (100 GHz optic BW). So, I can choose any electric modulation and any optic modulation, too. Anybody could help me? Any answer is welcome. Thanks.
  19. M

    Gambling problem/ standard deviation

    Read gambling problem/Standard deviation Posted: May 23, 2007 4:57 AM Click to edit this message... Click to see the message monospaced in plain text Plain Text Click to reply to this topic Reply I'm analyzing some data from online gambling sites.I'm trying to prove they are...
  20. P

    Lab write ups at the college standard

    how are they done at the college level? I would relaly like to compare actualy college level lab reports to my AP chemistry level lab reports. I know that they are usually done in pen and paper, but if someone could scan one so i could look at it I would greatly appreciate it thanks.
  21. I

    L'Hopitals Rule and Standard Limits

    Homework Statement Hello, I'm trying to find the limit(as n approaches 0) of [1-cos(n)]/(n^2). I have done a few of these before and haven't had to much trouble, but they all have been as n approaches infinity. Homework Equations I think the n approaches 0 is confusing me. The...
  22. L

    Express Imaginary number in standard form.

    Homework Statement Need to see if what I am doing is right, here is the problem: z= 4i/(-1+i), express z^20 in standard form. so, z= 4i/(-1+i) = 2-2i z^20 = 2*sqrt(2) x cis[20(-pi/4)] = 2*sqrt(2) x cis(-5pi) = 2*sqrt(2) x [cos(-5pi) + i sin(-5pi)] = 2*sqrt(2) x [-1 + 0i]...
  23. N

    Standard deviation of expectation values

    Very basic question which has confused me: if the variance of an expectation value <A> is: uncertainty of A=<(A-<A>)^2>^0.5 how is this equal to: (<A^2>-<A>^2)^0.5 ??
  24. P

    The kurtosis of standard normal pdf

    Hi, I'm tying to solve the fourth moment of pdf of standard normal pdf. meanwhile, i have to break this one: how to get the result of integral of x exp (x) dx. that would mean a great difference to me. thank you.
  25. F

    Standard Reduction Potentials of 1/2 Cells

    Homework Statement Use half-reactions and E's to determine the result of storing a solution of CuSO4 in a tin container. Homework Equations [Table of Standard Reduction Potentials of Half-Cells] The Attempt at a Solution My question isn't exactly how to do this question. I was just...
  26. M

    Comp Sci Why Does My C++ For Loop Increment Erratically?

    I wrote a program that is supposed to find the standard deviation of a set, but something really strange happens in a for loop that I have in my main function. int main() { int i=1; int NUMBER_OF_ELEMENTS; double data[NUMBER_OF_ELEMENTS]; cout << "Please enter the number of...
  27. E

    List of fundamental equations and constants of the standard model

    Hi Is there anywhere a list of all constants (with their values) and fundamental equations (which can not be constructed from any other equations) of the standard model? thx einKI
  28. Cyrus

    MATLAB Standard PPM servo interface with matlab

    I need some help here. I need to have a standard PPM servo interface with MATLAB so that I can give it a command in simulink and have a response. I found this device, which eliminates the need to use PPM in simulink. http://www.parallax.com/detail.asp?product_id=28823 Basically, it...
  29. D

    Using oxalic acid as a primary standard

    Hi. Can oxalic acid be used as a primary standard to standardise a basic solution, such as sodium hydroxide? I can't think of any reason why it couldn't be used, but i could very much be missing something.
  30. Gib Z

    Standard Form/Expansion of x^n - y^n

    Just as x^a-1 = (x-1)\sum_{n=0}^{a-1} x^n, is there a similar expansion for x^n - y^n?
  31. W

    How Do You Convert a Quadratic to Standard Form?

    Quadratic in standard form help...please Homework Statement Write the quadratic function f(x) = x^2 + 3x + 2 in standard form. Homework Equations Standard form equation : f(x) = a(x-h)^2 + kThe Attempt at a Solution Ok, I think I got this one but am wanting to be sure. I set it up : (x^2...
  32. wolram

    Is the Standard Cosmological Paradigm Explained Well by Hu and Dodelson?

    http://background.uchicago.edu/~whu/araa/node3.html I found this site, would it be a good reference?
  33. C

    Standard Deviation Problem in Physics. Help?

    Standard Deviation Problem in Physics. Help!? Homework Statement In working with Wheatstone bridge one student chose the value for R1 so that the bridge is balanced at L1 = 48.5 cm and L2 = 51.2 cm. If Each measurement has an uncertainty of +/- .05, what would be the minimum value for the...
  34. N

    Statistics: Mean and Standard Deviation

    Homework Statement In a recent survey, 80% of the community favored building a police substation in their neighborhood. If 15 citizen are chosen, what is the standard deviation of the number favoring the substation? Homework Equations I know that my mean is 15 and the probiblilty is 80...
  35. Q

    Standard representation of a vector space

    Hi everyone, Can anyone explain the following to me? Given a basis beta for an n-dimensional vector space V over the field F, "the standard representation of V with respect to beta is the function phi_beta(x)=[x]_beta for each x in V." This is from my textbook. It then proceeds to give...
  36. A

    Probability and I have a question about standard deviation.

    I have a question about standard deviation. If I have a hundred of distance data, how can I use standard deviation to choose a suitble range of the distance. What is the relation between standard deviation graph and my data. I can plot a graph using mean and std of the data, but do not know how...
  37. Garth

    Are high-z SNe Ia data reliable for measuring the evolution of dark energy?

    R. G. Vishwakarma has replaced his paper Recent Supernovae Ia observations tend to rule out all the cosmologies? with the accepted version. He does not say accepted by whom. (Emphasis mine) Does the high-z SNe Ia data record the evolution of Dark Energy, i.e. \omega, or the evolution of the...
  38. S

    What is the Missing Mean in a Sample of Size 5?

    Exam is in the next 30 mins so please reply ASAP. I just need help with this question. For a sample of size 5, x1 - mean = -5, x2 - mean = 9, x3 - mean = -7, x4 - mean = -2 and x5 - mean = 5 What is standard deviation... answer is 6.782 by squaring all the answers, dividing by n-1 and...
  39. quasar987

    Standard Basis and Ladder operators

    Cohen-Tanoudji defines a "standard basis" of the state space as an orthonormal basis {|k,j,m>} composed of eigenvectors common to J² and J_z such that the action of J_± on the basis vectors is given by J_{\pm}|k,j,m>=\hbar\sqrt{j(j+1)-m(m\pm 1)}|k,j,m\pm 1> But isn't is automatic that such...
  40. M

    Statistics: Standard Deviation Prob.

    Homework Statement This is my data: 42.4, 65.7, 29.8, 58.7, 52.1, 55.8, 57.0, 68.7, 67.3, 67.3, 54.3, 54.0 I need to find the standard deviation of this list of data. 2. Homework Equations standard deviation= : s^2=\frac{\sum_{i=1}^n(x_i -\overline{x})}{n-1} Actually the standard...
  41. S

    What Is the Minimum Temperature for Safe Commercial Flight Takeoff?

    Does anyone have any idea of general guidelines defining the minimum temperature at which a commercial flight can take off the ground? I understand that they generally use the criteria of ice to determine activity, but at a certain temperature is there a point of no go regardless of temperature...
  42. CarlB

    Category theory and beyond the standard model

    Kea tells me that a good first book to read to learn category theory is Sets for Mathematics $45 F. William Lawvere and Robert Rosebrugh Advanced undergraduate or beginning graduate students need a unified foundation for their study of mathematics. For the first time in a text, this book...
  43. B

    Standard Product Rule: Explained

    Hi, I'm having trouble following the following derivation I have seen in a textbook: The derivation goes as follows: L0P3+L1P2+L2P1=0 This is a Poisson eqn for P3 with respect to L0 which requires <L1P2+L2P1>=0 <L2>=L(BS)(sigma) <L1P2>=.5<L1.phi(y)>.x^2. d^2P0/dx^2 thus...
  44. M

    Could Theories Beyond the Standard Model Unify Forces in Physics?

    Have there been any theories in recent decades that suggest one? Or more? I know it may seem unnecessary or even frivolous, but theories beyond the standard model are, after all, grappling with issues like how the entire universe and its four forces came to exist. Has anyone postulated a fifth...
  45. Fredrik

    A problem with the standard solution of the two envelopes paradox

    The problem You have two indistinguishable envelopes in front of you. Both of them contain money, one of them twice as much as the other. You're allowed to choose one of the envelopes and keep whatever's in it. So you pick one at random, and then you hesitate and think "Maybe I should pick the...
  46. L

    Standard Compton Effect Explained Classically/Semiclassically

    I know this topic has already been covered many times, but, is it possible to explain classically or semiclassicaly the standard Compton effect?
  47. S

    Unwinding Spool vs. Standard Block

    Pulling an Unwinding Spool vs. Standard Block Homework Statement This problem is done on a frictionless surface There is a block pulled by a string with tension T. Next to it, there is a spool with a string wrapped around it and may unwind. It is pulled with the same tension as System A...
  48. S

    A model behind the Standard Model?

    Two interesting papers by Chan and Tsou on the hep-th arxiv: hep-ph/0611363 Title: Higgs Fields as Vielbeins of Internal Symmetry Space Authors: H.M. Chan, S.T. Tsou Comments: 24 pages An earlier suggestion that scalar fields in gauge theory may be introduced as frame vectors or...
  49. H

    Why Is FeSO4 Not a Primary Standard?

    feso4 is not a primary standard?? hi ppl, someone plssss help me---why is feso4 not a primary standard?
  50. 4

    Mean and standard deviation probability help

    A department store has determined that 25% of all their sales are credit sales. A random sample of 75 sales is selected and the proportion of credit sales in the sample is computed. a) What is the probability that the sample proportion will be greater than 0.34? my answer is: n=75 p=0.25...
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