Error Definition and 998 Threads

Hello! I am a bit confused about estimating the systematic error (I think it is systematic) from an experiment. Here is a (simplified) description of it. Assume that 2 groups measure the length of a cube with 2 different rulers, which, due to some effects give slightly different results (for...

I found the linearization, L(x) = -0.0001x+0.2 and I found L(1/99) = 0.0199989899. Then I tried to put that value into my percentage error formula along with 1/99 and got: the absolute value of (1/99)-L(1/99) and then we divide that by our actual value which is 1/99, then I multiply everything...

Hello! I have an experiment and for some reasons I was able to do only 4 measurements and they all ended up having the same value, say for the purpose of this post ##100 \pm 1## where the error of 1 is estimated based on the measuring device resolution. The mean is obviously 100. Usually the...

Hello! I have a fit to a histogram ##y(x)##. Now I want to predict the number of counts at some other point, not in the original data, using this fitted function and assign an error to it. Let's say that the the point where I want to compute this value, ##x_0## gives ##y(x_0) = 100##. As the...

I am trying a different energy spectrum in a code I am writing and get the following error when I try to run the it. 0.61247 0.88454 fatal error entry 2 of si 3 is not monotonically increasing This has me confused because the two values above are monotonically increasing as are the preceding...

Homework Statement: Physics Lab Propagation of Error Issue Homework Equations: ∂f/∂b=∂/∂b (tan^(-1)⁡(a/4b))= 1/(1+(a/4b)^2 )×(-a)/(4b^2 )=1/(1+((5.922 cm)/(4×1.766 cm))^2 )×(-5.922 cm)/(4×(1.766 cm)^2 ) Hello, I'm trying to find the uncertainty in a function from the lab manual for the...

How should I do to eliminate the error message? In what direction should I approach the question? (I have tried difference combination and sequences of the heat exchanger below pinch, all seems not working) Thanks

Hello! I have some measurements with errors associated with them: ##x_i \pm \delta x_i## and I want to cite the value of the mean with its error. I see online that the error on the mean is defined as ##\sigma/\sqrt N##, where ##\sigma## is the standard deviation of my measurements and ##N## is...

I have been encountering "zero lattice element hit" when I try to run it in MCNP5. The input file is provided below. The square lattice runs fine, but the hexagonal does not. Hope someone can help me here. Thank you.

Hello, I am working through the MCNP manual and am experiencing the following error as well as warning when trying to run the sample problem from the manual. The fatal error I get is "fatal error. surface 0 not found for cell 1050." I have upload the output file with the errors in case I...

I am curently working on Forecast in cosmology and I didn't grasp very well different details. Forecast allows, wiht Fisher's formalism, to compute constraints on cosmological parameters. I have 2 issues of understanding : 1) Here below a table containing all errors estimated on these...

I am studying QFT from the book A First Book of QFT. I am currently in the chapter of QED. The authors have written down the interaction Lagrangian for QED. Thereafter, they have taken a special case of the electron, and written down the normal-ordered interaction Hamiltonian for this case...

In general the probability of getteing at least one type I error is P=1-(1-a)^m. With m being the number of tests and a the probabiliy of getting a type I error. But i do not know how to get an expression with m0

I am trying to solve the equation like this, from sympy.solvers import solve from sympy import Symbol import math x = Symbol('x') A, B, C, D = 0.59912051, 0.64030348, 263.33721367, 387.92069617 print(solve((A * x) + (B * math.sqrt(x**3)) - (C * math.exp(-x / 50)) - D, x , numerical = True))...

About cosmology: https://www.physicsforums.com/threads/what-is-the-probability-that-the-universe-is-absolutely-flat.971984/#post-6180036 Planck paper: https://arxiv.org/pdf/1502.01589.pdf As in PCP13 we adopt a Bayesian framework for testing theoretical models. In the Planck paper, pages 38-40...

This is a known issue all over the net, and with almost all versions of Android, from KitKat to Oreo. If you have enabled contacts sync with Google, you might get the following error if you head to Accounts section under Settings, and then select Google: No official solution has been rolled...

1st page of Chapter 7, p.276, very last line, p=p'. I get that in Newtonian mechanics, the forces, times and masses are the same in two different inertial reference frames, but shouldn't the momenta measured be different?

NOTE: this is a programming exercise (Python). I started adding to ##x_{true}## an error related to a (for example) 10% relative error, obtaining ##x_{measurement}##. Then i computed ##y_{measurement}##. To find the precision, i calculated ##(y_{true}-y_{measurement})/y_{measurement}##. If it is...

I have the following problem: Use the total differential to calculate approximately the largest error at determine the area of a triangle rectangle (right triangle) from the lengths of the cathetus if they measure 6 and 8 cm respectively, with a possible error of 0.1 cm for each measurement. I...

In "The Theoretical Minimum" (the one on classical mechanics), on page 218, the authors write a Lagrangian $$L=\frac m 2 (\dot r^2 +r^2\dot \theta ^2)+\frac {GMm} r$$ They then apply the Euler-Lagrange equation ##\frac d {dt}\frac {dL} {d\dot r}=\frac {dL} {dr}## (I know there should be...

The error ##e_{n}(y)## for ##\frac{1}{1-y}## is given by ##\frac{1}{(1-c)^{n+2}}y^{n+1}##. It follows that ##\frac{1}{1+y^2}=t_n(-y^2)+e_n(-y^2)## where ##t_n(y)## is the Taylor polynomial of ##\frac{1}{1-y}##. Taking the definite integral from 0 to ##x## on both sides yields that...

I am trying to run explicit dynamics, but after AUTODYN PRE-SOLVER SETUP is complete the solution stops and the following message is displayed "A general failure occurred during the solution process." I have installed the same ansys version on another pc and everything works ok. RAM is the...

Hello, I am working on a MATLAB project for my intro to MATLAB course. My project evaluates certain parameters of a spring mass system and graphs the result along with a little mock animation. inputs the user is allowed to change: Initial Position at time =0 Initial Velocity at time=0 Mass of...

This is a fascinating discussion. I know some people don't want to debate this or they can't debate it but the truth doesn't care about your feelings. This isn't speculative, it's backed by Scientific research. First paper. Is Spacetime an Error Correcting Code. Published in the Journal of High...

I know I am posting this in the wrong sub-forum, but I am unable to enter certain sub-forums (and when I login I just get a "security" error), where as in other sub-forums I am automatically logged in. Is there a problem with the site or just me experiencing these problems?

I'm confused as to why this bubble sort I'm implementing is setting _all_ items to one of the items (I have no idea which one as array is too big) the data type is of ... [[1128 1026 1192 1023]] [[ 771 195 858 196]] [[ 953 1799 955 1738]]] when I have an array of int, this same algorithm...

If someone can straighten out my logic or concur with the presence of a mistake in the proof (even though the conclusion is correct, of course), I would be much obliged. I’m looking at the proof of the corollary near the middle of the page (image of page attached below). I simply don’t find...

I am using the TMESH tally to try and get the flux of a 1 MeV point source through a spherical MESH a distance of 1cm away from the origin and covering all polar and azimuthal angles. When I try to plot using the RUNTPE function I get the error "no tally no plot". I also do not see tally...

Mentor Note -- Thread moved from the technical forums, so no Homework Template is shown. So, we've conducted an experiment on resistors in a circuit. The theoretical calculation was based of on E-24 series color band table and the measured resistance of the resistor was measured by a meter...

(A)My textbook states the following : (1) The example explaining the italicised statement is rather confusing. My understanding of the statement is that we need to include one extra significant figure than what the relevant rule requires us to round off to, for intermediate...

I got the first part of it down, $$L=\int_1^5 \sqrt{1+(\frac{1}{x^2})}dx$$ I just want to know if it's right to make your ##f(x)=\sqrt{1+\frac{1}{x^2}}## then compute it's second derivative and find it's max value, for the trapezoidal error formula.

I'm new to fortran coding and trying to read a file called "data.dat" with data like a triangular matrix 0.1 0.1 0.2 0.1 0.2 0.3 0.1 0.2 0.3 0.4 0.1 0.2 0.3 0.4 0.5 using the code PROGRAM matrix IMPLICIT NONE REAL, DIMENSION(5,5) :: a INTEGER :: row,col,max_rows,max_cols max_rows=5...

1. If we descended from an unknown common ancestor that was a step up from chimpanzees and bonobo's, then by biological definition, shouldn't chimpanzees and bonobos be much more wise and more intelligent than humans as they are the ones who came first through evolution before our unknown common...

Homework Statement I got an experimental vertical acceleration of -12 m/s^2 of projectile motion for an experiment I did at home where I just had to throw a ball at around 45 degree to the horizontal up in the air and record it's motion, then analyze the motion via computer software. Obviously...

Homework Statement The following may appear to be a rather strange question but I have no access to a lab to conduct experiments so I have to rely on my imagination, and questions from textbooks, to contrive questions that will hopefully improve my understanding of a topic. I have recently...

Homework Statement Homework Equations Fg=mg The Attempt at a Solution I tried to set this up as two "triangles". && left triangle: sin(37)=mg/T T1=mg/sin(37) T1=202.72 right triangle: sin(53)=mg/T T2=mg/sin(53) T2=152.761 I now know the correct answers are T1=73.4N and T2=97.4...

Homework Statement An object of mass m=2.3±0.1kg moves at a speed of v=1.25±0.03m/s. Calculate the kinetic energy (K=1/2mv2) of the object and estimate the uncertainty δK? Homework Equations - Addition error propagation--> z = x + y and the Limit error--> δz = δx + δy -...

Okay, so I did an elastic collision with Vernier carts and magnets. The results seem pretty good. Cart one started with -0.1205 kg*m/s ended with +0.1027 kg*m/s Cart two started with +0.1174 kg*m/s ended with -0.1118 kg*m/s So Total before = -0.0031 kg m/s and total after = -0.0091 kg m/s. If...

Homework Statement : [/B]Write a C program to print hello world 2. The attempt at a solution: I am completely new to programming. I am learning C at present. In my college, we use linux. Since my pc has windows installed so I am using cygwin terminal to use linux commands from windows. I am...

On the following page on wikipedia: https://en.wikipedia.org/wiki/Fixed-point_iteration the section "Examples" has a second bullet point, where the author suggests ##q=0.85##, but how did they get this number? I tried googling everything and could not find out how ##q## is determined.

Homework Statement I want to try to derive the rocket equation and then add additional effects like gravity, air resistance, etc. Here's the equation that I found online: Homework Equations p (momentum) = mass * velocity F (force) = Δp / Δt The Attempt at a Solution [/B] pi = mv Here is...

Hello, I am working through the MCNP6 manual and am experiencing the following error as well as warning when trying to run the sample problem from the manual. The fatal error I get is "fatal error. 1 entries not equal to number of cells = 4." From the IMP card. My entry for...

Thought you all might be interested in this article. It could just be hype, but there also might be something deeper to it. You hear of so many schemes of tying together quantum mechanics with a relativistic understanding of gravity, that it's easy to respond to yet another announcement like...

If given two variable of the form p=x±δx and q=y±δy where δx and δy are the error obtained while measuring p and q and x and y are it's absolute value obtained. We define R=p+q,p-q,p/q,pq In each of this case I want to know what will be the error in R.(e.g δR) Thank you

Hi All, I was trying to help someone in a question for the actuary exam. I wonder if there is a mistake or whether I am missing something obvious here: What is the age a 90-year old man can expect to live given the probability an x year old man will live until age x+1 is given by ##...

Homework Statement The op amp has a near ideal level 1 model with G = 5000V/V, ri = inf, ro = 0 How would I obtain the feedback function? Homework Equations I know I have to find the feedback function which is: f = - (ΔV/Vin) The Attempt at a Solution I will first drive using the...

Homework Statement I need to calculate the error of an average value (N for diffraction grating). My results were 4 different average angles. With which I calculated their uncertainty using std. Using equation (1), I found the number of lines per meter (N) with a known wavelength (λ) and the...

Hey there, First time on this forums, looking forward to some interesting discussions :) I am currently trying grasp the concepts of error propagation and standard deviation in relation to experimental physics. I have some data set and i want to determine the difference between the measured and...