Error Definition and 998 Threads

Hello all, I am in a total state of confusion with regard to this. Here is question. The length of a rod is [11.05 (+/-) 0.2]cm. What is the length of two rods? I want to know should the answer be reported like [22.1(+/-) 0.2] or [22.1(+/-) 0.4]. Regards:)

Hello, can you help me? In my model, I have to simulate source distribution in two volumetric cells (30 and 31). For example, with a photon source of 356 keV, I have to simulate the distribution according 0.2 (20% in source 30: thyroid without nodule) and 0.8 (80% in source 31: nodule). I use...

Homework Statement The internal and external diameter of a hollow cylinder are measured with the help of a vernier calipers. Their values are (3.87 ± 0.01) cm and (4.23 ± 0.01) cm respectively. The thickness of the wall of the cylinder is ?Homework Equations Thickness of cylinder wall= 1/2...

Hello everyone here, I do need your help in this matter, please kindly help me solve this problem. I am new to this forum and now am seeking for help. I am new to MCNP code, and I run MCNP6 code using BURN card and it give me fatal error say "Model required. Cannot use memory reduction...

Homework Statement Prove the equation for ΔRC. (See the first attachment with the circuit schematic inside) Homework Equations (The equation for RC, in both attachments) The Attempt at a Solution You can see my attempt at a solution in the second attachment. I'm stuck at the step shown in the...

Description of the situation I have measured the incident number of electrons in a channel electron multiplier at different light polarization angles (a photoelectron angular distribution measurement). The events follow a poisson distribution and as far as I know the number of electron counts in...

During a lab exercise we measured different masses of a magnetic material on a scale while changing the strength of the magnetic field it was in. Afterwards we plotted the masses and the fieldstrength hoping to find a linear slope. Then we drew a linear slope by using linear regression and found...

During a labexercise we measured a value to be 26.3 mT. The teslameter was said to have an accuracy at +- 0.05%. This means we measured 26.3 +- 0.0132mT. However we are supposed to write a measured value with it's error in the last digit. But the error is smaller than the smallest digit we got...

Hi, I am reading the biography "Einstein's greatest mistake" from David Bodanis. On page 39 the author explains some of the consequences of relativity by referring to (although he doesn't mention it by name) the twin paradox. He explains that someone accelerating at high speed away from Earth...

Hi. Suppose I have a function y=f(a,b;p;x) where a, b are known with some uncertainty and x, y were measured multiple times. I want to find p through best fit. I consider a, b to be gaussian variable. I can imagine multiple ways to do this: * I consider a, b parameters like p. I don't like...

Homework Statement Suppose the STM tip current is given by i = aV e^{-A\phi^{1/2}s} a) Derive an expression for the fractional change in tip current as function of fractional change in tip spacing s. b) If \phi = 4V select a reasonable set of V values so that a 1Å increase in s will cause...

Let's say I take 3 measurements, and each measurement has its own uncertainty: M1 = 10 ± 1 M2 = 9 ± 2 M3 = 11 ± 3 I want to quote the average, and the net uncertainty. I understand that the uncertainty of the mean is: (Range)/(2*√N) where there are N measurements. So: (11 - 9)/(2*√3) = 1/√3...

HI Guys, I am getting an error in Ansys Maxwell that says Maxwell2d solver, process solver2d: Internal Solver Error: 'In the Material: M270-35A_12 , the SLOPE of the End Two Points in this BH curve is 56519.1, which is more than 2 times of Mu0; This may lead to a non-physical solution...

Dear all I am doing a simulation of a 3 phase transformer. I am adding the excitation using external circuit in Simplorer , I am getting these error ! Can somebody comment on the error . An external simulator couldn't be setup for simulation. (12:01:33 PM May 02, 2017) Simulation completed...

Homework Statement Compute the moment of intertia Io of the two cylinders, per their axis of symmetry, and then, using Steiner's formula, the moment of inertia Ib, as per the axis of rotation. Homework Equations Io = 1/2*m*R2 Ib = 2*(Io + m*x2) The Attempt at a Solution Now, this is...

Homework Statement Run a transient simulation and plot the three outputs, Vo(t), on the same plot. Use the following settings: 1. Set the Run Time (or Stop Time) so that you plot 3 cycles of Vo(t). 2. Set the Maximum Step Size so that you get at least 100 points per period for Vo(t). 3. Set...

Hi all. I ended up to this section in K&K (2nd edition, but with 1st is the same) when they derive the wobbling motion of a simple body in torque-free precession. [see the attached file] Equations 8.23 and 8.24 are integrated into 8.25[a|b], but I think signs are wrong. Shouldn't be negative...

Hi PF! I'm solving an PDE where the analytic solution is called ##F(x)## (unknown). To approximate the analytic solution I made a naive expansion in some small parameter ##\epsilon## such that ##F(x) = f_0(x)+\epsilon f_1(x)+O(\epsilon^2)##, where I know ##f_0(x)## and ##f_1(x)##. I then...

Hi. Let's say I have data which I have measured. For example I measured a length of an object and the measurment was repeated 5 times. An instrument which I used to measure has an error, value of which I know. My options are to either to just go with the instrument error (probably not, right?)...

Hi. In my (German) physics lecture notes, I found this depiction of a Stirling engine: According to the text, it should be A: isothermal expansion B: isochoric cooling C: isothermal compression D: isochoric heating This seems correct for the PV diagram, but strange in the illustration on the...

Kind of a silly question; can pie charts have error bars? I have used x-ray dispersion to find the approximate chemical composition of unknown samples. Is it appropriate to have error bars on how much we expect the percentages to deviate statistically throughout the sample? Or, should I go a...

I've been on http://300mclub.org/ for years and years. Recently I am getting a 403 forbidden error. They're recently had complete software changeover (i.e. pretty much since the last time I logged in). They are insisting it has nothing to do with this. They have double checked my IP and...

New article, abstract: http://science.sciencemag.org/content/355/6331/1330 abstract:

Hello everyone! I would like to ask you if anyone can help me solving my Problem with mcnpx. I created a file with a watertank, a nozzle and a slit blend on the surface. I also inserted a protonbeam and would like to plot the dose and fluence for examplte with Moritz. But when I execute the...

hi everyone, i have a mcnp error, it don't finish, it only run a half! i hope someone can help me! thank you! and my code JCO c cell cards 1 1 -0.00117 -100 300 2 2 -1.52 (-100:-101) -300 #1 $solution 3 4 -7.93 (-110:-111)#1#2 $clad 4 3 -1 (-200:-201)#3#1#2 $water 5 4 -7.93...

1. The problem statement of my lab I have this physics lab where I have to find the maximum velocity and maximum acceleration of a high school student sprinting/running using carbon tape and a spark timer. Which I already did. Now I'm having trouble developing my sources of error section. I hope...

I have a PC(as master) and a compressor(as slave) in modbus communication. I am using 1000ft cable and I want to analyze the interference effect on the data communication error. I am coupling burst signals produced by the relay switching and I could observe the level of burst to be ~50V. When I...

I have conducted a tensile test on five specimens. I intend to do a linear regression for every set of data and get a value for the slope (modulus of elasticity) and its error by finding the standard deviation (using LINEST function on excel) of the slope. I will now end up with 5 slope values...

Let ##j^{\mu}(x)## be a Lorentz 4-vector field in Minkowski spacetime and let ##\Sigma## be a 3-dimensional spacelike hypersurface with constant time of some Lorentz frame. From those I can construct the quantity $$Q=\int_{\Sigma} dS_{\mu}j^{\mu}$$ where $$dS_{\mu}=d^3x n_{\mu}$$ and ##n_{\mu}##...

I am trying to find or develop an algorithm that can take a 1024 (lets assume random) bit array (so 128 bytes) and, by adding some redundancy (making the final code more than 1024 bits long), make it capable of decoding the data with up to n random bits flipped. Important point is that it has...

What it does is described well in my comments. I'm using decimal, which is more precise than double but has a smaller range of values. https://msdn.microsoft.com/en-us/library/ms228360(v=vs.90).aspx const decimal pi =...

I'm trying to draw a circle and a (possibly rotated) square on a grid. I have the circle part down and it's the square that is giving me trouble. I am originally given 2 points which represent the coordinates containing opposite ends of the square. For example, those 2 points would be (8,14) and...

To learn LaTex, I want to install MikTex but in installing it, I come across with a problem. It appears when click next. What is the problem and how can I solve it? Thank you.

#include<iostream.h> #include<math.h> #include<conio.h> void main() { int n,fact(); float LAM, MU=3, RO, C=0.1, N=10, F1=0, EXX, EWQ; clrscr(); for (LAM=0.1;LAM<=1.1;LAM=LAM+0.1) { RO=LAM/MU; EXX=2/(MU*MU); for(n=1;n<N-1;n=n+1) F1=F1+(N-n)*pow(LAM*C,n-1)*exp(-LAM*C)/fact(n-1)...

Hi. I have a simple circuit with a third-part model. As far as I can tell using info from the internet I have everything correct, but I still get this problem. Please help me clear this log-jam, thanks!

I've come across many instances where sometimes the error tends to zero but other times it does not. Let me give you a few examples. 1. When I calculate the volunme of a sphere summing up discs of height dy from -R to +R, the error in volume tends to zero as Delta y->0 but when I'm calculating...

Hey! :o A vegetable trader sells potatoes in 5 kg bags. Since potatoes differ in size, it is difficult to ensure that in each bag are exactly 5 kg. The dealer claims that the average weight of the potatoes was 5 kilograms. This has to be checked with a sample. The sample (n = 25) gives an...

I am carrying out a transient analysis of an electric motor. After running up to 250 ms it is showing an error that core loss values cannot be recovered and I am not able to run it further. Please help me to resolve it so that I can carry on ahead with my simulation. Thank you in advance.

Homework Statement [/B] After doing a lab on air compressors, we were asked to calculate Error in Pressure, Temperature and time measurements taken (all at 30 second intervals). We took pressure and temperature values at time = 0,30,60,90,120,150 and 180 seconds. We repeated the experiment 5...

Homework Statement I have to calculate the propagated error on g of pendulum. I pretty much measured the T of pendulum and now calculating g while increasing the number of cycles. Homework Equations I used the equation of propagated error and i included picture of it and my calculations. The...

Homework Statement A student performs a series of measurements, the obtained values are : 90, 110 and 180. The method that is used has a theoretical error of 5%. What is the real value of the measurement and empirical error ? What are the conclusions ? Homework Equations We have no equations...

The Landau Lifshitz book "Mechanics" has a good reputation of one of the best books, not only on classical mechanics, but on theoretical physics in general. Yet, I have found a serious conceptual error (or at least sloppyness) in it. Sec. 23 - Oscillations of systems with more than one degree...

I'm learning about derivatives and on the website they put the value x^2 into f(x + dx) and it became (x + dx)^2 Shouldn't it be (x^2 + dx^2) ? It's the last example https://www.mathsisfun.com/calculus/derivatives-dy-dx.html Thanks in advance!

I try to solve a block diagram reduction example but when I did the operations, sign of one operation is incorrect. I tried to understand why it is so? Would somebody like to help me. (1) First I carry the feedback into the parallel line. (2) I add +1/G1H1 in the parallel line because I...

i am trying to run my mcnp input file and these are the error messages which i do not no how to fix them.

I need help with creating repeated structures. I have a hexagonal aluminium container, inside of which i need to put cylindrical rods. I defined a rod and its cladding and air surrounding it, as universe=5 then i defined another hexagonal surface with 0 material but fill=5 and i define this...

Hi, I'm looking at an Italian high-school physics textbook. The subject is uncertainty propagation, and the target is 9th grade students. The book is allegedly by J.S. Walker, but I'm not sure how much it was "redacted" by the Italian editor. I am a little puzzled by two rules that are stated...

Question :- The critical volume of a gas is 0.072 L mol-1. What will be the radius of the molecule in cm ? Answer in the book :- ##V_c = 3b \implies b = 0.024 L mol## ##\therefore## for every molecule ##b = {24 \text{cm}^3\over 6 \times 10^{23}} = 4 \times 10^{-23}\text{cm}^3## per...

Homework Statement I have calculate my double integral using wolfram alpha , but i get the ans = 312.5 , but according to the book , the ans is = 0 , which part of my working is wrong Homework EquationsThe Attempt at a Solution Or is it z =0 , ? i have tried z = 0 , but still didnt get the...

NOTE: I seem to have a dental implant in which there has been a mechanical failure of the abutment, which has piqued my interest in this. The paper is here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4668729/ About 40% down, there is: *** The most commonly used retaining screws are either...