Errors Definition and 328 Threads

haruspex submitted a new PF Insights post Frequently Made Errors in Mechanics - Momentum and Impacts Continue reading the Original PF Insights Post.

haruspex submitted a new PF Insights post Frequently Made Errors in Mechanics - Hydrostatics Continue reading the Original PF Insights Post.

haruspex submitted a new PF Insights post Frequently Made Errors in Equation Handling Continue reading the Original PF Insights Post.

haruspex submitted a new PF Insights post Frequently Made Errors in Mechanics - Kinematics Continue reading the Original PF Insights Post.

haruspex submitted a new PF Insights post Frequently Made Errors in Mechanics - Moments Continue reading the Original PF Insights Post.

haruspex submitted a new PF Insights post Frequently Made Errors in Mechanics - Friction Continue reading the Original PF Insights Post.

haruspex submitted a new PF Insights post Frequently Made Errors in Mechanics: Forces Continue reading the Original PF Insights Post.

The inspiration for this thread is the following question: "Without further calculation, say whether the observations are consistent with the set of values [1.215; 1.216; 1.209; 1.212] independently reported for c." I had previously found that c = 1.150259067 = 1.15 (3sf) and from error...

Hey guys, I'm pretty new and desperate. I been trying to compile this program for a while and keep jumping from error to error. Currently I have the following error: Error: Rank mismatch in argument 't' at (1) (scalar and rank-1) I have checked that my arrays are correctly. I have checked that...

When the learning combination formula the formula nCr is usually derived using a deck of cards. There are n=52 different card. If you choose r number of cards, each is different so you basically start with n!/(n-r)! , then because the order is unimportant multiply by 1/r!. This explanation is...

Hello! (Wave) We consider the initial value problem $$\left\{\begin{matrix} y'=y &, 0 \leq t \leq 1 \\ y(0)=1 & \end{matrix}\right.$$ We apply the Euler method with $h=\frac{1}{N}$ and huge number of steps $N$ in order to calculate the approximation $y^N$ of the value of the solution $y$ at...

Homework Statement I m not able to understand one of the methods to reduce error in measurement using ac bridges. "All the leads to a single corner should be brought as nearly as possible to the same point" Homework Equations I am providing the bridge layout image and a,b,c,d are corners of...

Homework Statement Hi, please could someone give me some guidance on how tolerance should be calculated in physics. If given the following statement: (x-t) is proportional to p and then asked to show whether or not your measurements of these values support this statement within a tolerance of...

Homework Statement Hey guys, so I'm doing the an exercise on the Kater's pendulum, to calculate g. I've gotten down my g calculation to g = 9.80658m +/- 0.00054 using equation 1 below. The errors taken into account are just on the kater period T and the distance between the two pivot points (L)...

Homework Statement There are 5 errors, and 3 people are proofreading the text. P(1. person finds an error) = 0,5 P(2. person finds an error) = 0,6 P(3. person finds an error) = 0,7 There are 5 errors, and whenever a person comes across one, they have the above probability of seeing it...

Homework Statement For my coursework task, i am to quantify and discuss errors associated with an experimental procedure. This involved a thyristor control unit which allowed the firing angle of two thyristors (in a half controlled bridge rectifier) to be varied with a rotary dial or pot/rheo...

I have set of date with error bars of different length on my y values. I want to know what the error is on the slope and intercept of my line of best fit through this data. Is there a numerical way to calculate this that takes into account the fit of the regression line and the y error bars?

I have several measurements taken over a time series. Each data point has a standard error value. I need to sum up the data points, and determine the error associated with that sum. The error values across the time series are non-normal, so I'm assuming that I can't use the usual error...

A number of popular-level articles have been published saying that RAID5 is increasingly impractical at larger data volumes due to the chance of an individual HDD having an unrecoverable read error (URE) during the rebuild phase. I think the underlying math which produced this conclusion may be...

I'm not really sure where this thread belongs... Do you know any (free) program that can allow to build bands (instead of just line curves) to take into consideration the errors of a graph? eg if I want to draw: y= bx + (c \pm \delta c) to get something like the yellow band in this (of course...

Classical Mechanics by Herbert Goldstein is one of the most used textbooks on this subject, perhaps the most used one. However, I found a couple of errors in Section 4.9 (in 3rd ed, written with Charles Poole and John Safko) about rotations. First, at p. 172, the angular velocity vector ω is...

I have one fast question. How can people in some results, distinguish between systematic and statistical errors? So that they can write: x= A^{\pm \delta B (stat)}_{\pm \delta C (syst)}? I am trying to do the same with a report of mine, but I am not quite sure about whether that's possible or not.

I wanted to ask something concerning the errors... Why sometimes the errors are taken to be \sqrt{N} where N is your measured value (such as the number of counts from a detector) and why is it sometimes given as half of your device precision (eg a common ruler's error is 0.5mm)? In my case I...

Hello, I am having a hard time getting my errors to come out to what the book says the answers should be. My approximations are correct, so I think I'm just misunderstanding how to find K. Q.a) Find the approximations T8 and M8 for ∫(0 to 1) cos(x2)dx I found these to be T8=0.902333 and...

Hey Everyone, I know I just posted yesterday, but I have another problem from the first chapter of my Calc 2 summer course that I would like to iron out. Integral of (5/x)dx from 1 to e with n=4, 8 finding both Trapezoid rule and Simpson's rule approximations, and their errors. I know how to...

I am trying to do an introductory course on C++ through OCW (MIT). However, there is this one they tell you to try that I keep running into a problem with. This is the information they tell us to input: #include <iostream> using namespace std; int main (){ int x; cin >> x...

Homework Statement What are the potential errors in measuring strain with strain gages? How can these errors be minimized? The Attempt at a Solution In my class notes, I have the four Errors. 1-Gage mounting (glue thickness & flex) Use a thin layer of glue and make sure the layer is smooth...

Homework Statement Part (a): Find an expression for intensity, interference phase and total change of interference phase. Part (b): Find an expression for <L1>/L0 and its error. Part (c): Find an expression for Δø1 and proportionality constant. Part (d): Find an expression for n(0) and α...

I use the least squares method in a small C-programm to fit some data points. But don't know how to get the errors of the calculated parameter.

Homework Statement Hi, I have to do a simulation of two non linear dynamical equations which represent a electromechanical system. (An inverted pendulum attached to a cart moving over a rail). I am going to simulate the response via numerical methods programmed in LV. (I am trying firts with a...

Hi, I have a question to ask. On my notes that my teacher gave me, he said that there are some errors in the notes. He had not responded to me which are the errors yet but he said about zero errors in vernier calipers and micrometer screw gauge. The question is: On my notes, it says that...

Hi, Homework Statement A quadratic piecewise interpolation is carried out for the function f(x)=cos(πx) for evenly distributed nodes in [0,1] (h=xi+1-xi, xi=ih, i=0,1,...,πh). I am asked to bound the error. Homework Equations The Attempt at a Solution I believe the error in this case is...

Hey! I am looking at an exercise in Numerical Analysis and I got stuck. Why do we have a huge error when we substact two almost equal numbers?

Background: My lab group has taken a number of measurements of gas levels over 15 minute period every 15 seconds. We actually used a gas sensor and computer interface to do it so it pretty much did all the work. In calculating the errors for the data, using the uncertainties given in the user...

Hi I have these functions: void posicaoIfElse (int e [][n], int i, int j, int k, int m, int n) { ... ... } void posicaoFormula (int e [][n], int i, int j, int k, int m, int n) { ... ... } that I calls through posicaoFormula (e,i,j,k,m,n); printf ("\n"); posicaoIfElse...

1. The question The following message was originally transmitted with odd parity in each short bit string. In which strings have errors definitely occurred? 11001 11011 10110 00000 11111 10001 10101 00100 01110 2. The attempt at a solution It says that it is transmitted with odd...

I am interested in a subject that is only tested on exercises, however it has also a lengthy theory. I have gone through the theory and I have made notes on parts I wasn't aware of at first. I have also gone through the introductory exercises by myself and I have made notes on points I wasn't...

Hi guys, I've been struggling with this concept for a few days now. I have this *good* image that I am blurring (using a gaussian blur), then adding some small percentage of gaussian white noise to it. Then from that image, I want to compute the naive solution (just assuming B=AX and solving...

Homework Statement In a lengthy manuscript, it is discovered that only 14% of the pages contain no typing errors. If we assume that the number of errors per page is a random variable with a Poisson distribution, find the percentage of pages that have: Exactly one typing error, At the most 2...

why errors are growing beyond courant number limit? i know that it depends on the scheme which we applied to the problems. But why it is ? which property leads it to stable or unstable region during Fourier analysis?

I am trying to write a program that in Fortran 95 will integrate x^2 from 0 to 1. Easy right?? I'm getting errors, though, that I really don't understand. Here is my code: [FONT="Courier New"]program montecarlo2 implicit none real :: fmax,iseed,srand,xmax,x2,x,y !why do we need pi...

Homework Statement I'm currently writing a program that will read in a list of gaussian distributed random numbers as an array and will make a 'measurement', that is they will be assigned to another array with an associated error. This is to try and simulate the communication of Alice to Bob...

So I have a histogram with bins that contain the number of events expected at a specific energy (which I generated with a Monte Carlo).. I need to add (integrate) all the bins in a section of this histogram and find the error of this value. However, the number of events are very small approx...

It is proposed to use a katharometer to mesaure the amount (about 5%) of oxygen in nitrogen, in the presence of a small amount (0.5%) hydrogen. How constant would the proportion of hydrogen have to be in order to limit errors in measurement of % oxygen to +/- 0.1%? The thermal conductivities...

does a hamming code always corrects one error and detect 2 errors ? and is the distance always 3 ? I know that that is true for (7,4) hamming code but does that apply to a (11,7) or (15,11) ? if not please let me how to get the answers

I need your opinion/help, guys. Well-know American logician H. Curry once expressed the opinion that in spite of the fact that it seemed to be absolutely impossible to explain Russell's paradox in terms of conventional 19th century logic, it may happen in modern days that some error would be...

I learned that random errors cannot be controlled and cannot be eliminated but only be reduced (averaging allows a result that is below the accepted answer to be accounted for by another result that is higher than the accepted result) and so it would cause bad precision. While systematic errors...

Hi! Slightly oddball request. A nice, but mistaken guy has produced this website-http://www.dynamic-soaring-for-birds.co.uk/ and further written about his ideas here-http://www.bou.org.uk/dynamic-soaring/ He contends that Dynamic Soaring is possible utilising a constant horizontal...

Hello Everyone, I am trying to compute the standard error of a stress related calculation. Let's consider the following: A ± ΔA B ± ΔB where A and B are the mean values while ΔA and ΔB are the respective standard errors. The common combination of errors formulas are as follows: y = A +...

Hello Everyone, I am trying to compute the standard error of a stress related calculation. Let's consider the following: A \pm \DeltaA B \pm \DeltaB where A and B are the mean values while \DeltaA and \DeltaB are the respective standard errors. The common combination of errors...