What is Error analysis: Definition and 100 Discussions

Homework Statement Hey guys, I have recently done an experiment in regards to the acousto-optic effect (which in itself is freaking amazing!). And i need to do an error analysis for my value of the phase velocity. I believe i have made a mistake but i can't find it anywhere. Firstly i have...

Hey there, This isn't exactly a homework question, but my question did arise while doing homework and I wouldn't know where else to post it, so here I am. I'm a Calc 2 student and covered approximations of integrals that I normally wouldn't be able to integrate today. I was going through the...

Homework Statement Consider the function F(xyz)=x^4+5y^4+2yz+3. Let the uncertainty in x be represented by the variable dx, the uncertainty in y be represented by the variable dy, and the uncertainty in z be represented by the variable dz. Find an algebraic expression for the uncertainty in...

I've done a decent amount of reading on the subject, and I used this method of course when reporting errors during lab experience I got as an undergraduate, but it was never quite fully explained to me why exactly we report a value +/- the standard deviation of the mean as our result. Why not...

I was recently told I needed to review some material and they recommended I look at Bevington: http://books.google.com/books/about/Data_reduction_and_error_analysis_for_th.html?id=0poQAQAAIAAJ I haven't had a chance to look at it yet, but I was wondering if anyone had any other...

Homework Statement Alright so I'm writing a lab report and I am running into a problem of finding the error on this value. I am measuring the magnetic susceptibility of a couple of samples. My lab manual and instructor told me the error on the force is related to the error on the derivative of...

Equation: M (ΔT)= The question: If ΔT has an error of one degree, and i multiply it by the mass of an object (m) is the error in y still one Attempted answer: or is it proportional to M i.e Δt plus or minus 1 degrees so the error in y is 2M? P.S i need to be able to know the error...

Hello everyone I am solving an electrostatic problem (with analytical solution) using a finite difference method and I want to plot the error of the FD against the analytical solution. What would be a good way to measure the error? I tried the relative and absolute error, but since values...

I'm dealing with a histogram and want to use poisson errors for each bin. For example, having 7 items in a bin gives that bin an error of sqrt(7). I'm comparing four different data sets, each with different sizes. I'm scaling everything in terms of probabilities so the four data sets can be...

Homework Statement I have three measurements for the L, W, H of a box: 40.4, 14.9, 17.0. the volume would then be 10233.32cm. each of my measurements has three sig figures, and it says in my book that with multiplication the product should have no more sig figures than the measurement with...

Homework Statement doop=a^{3}/(a^{3}-(b^{2}*d*s0/L) a=4.65+-0.03 b=4.60+-0.03 s0=3.987+-6.906e-3 d=5.05+-3.03 could someone please check that if they get the same answer as me: doop=1.021+-1.3e-3 Homework Equations The Attempt at a Solution Homework Statement Homework Equations The Attempt...

Homework Statement let x=2±0.2 y=sin(x) write y in the form mean±error i don't know how to perform error analysis on the sine function help please Homework Equations The Attempt at a Solution i looked through a physics textbook and saw something which might help me...

Homework Statement In this experiment, the acceleration due to gravity is related to the time, t, it takes the ball to fall to a distance , y, by Eq. (3). With this equation and Eq. (2), show that the fractional error, ∆g/g is ( (∆y/y)^2 + (2∆t/t)^2 ) ^1/2 Homework Equations Eq. (3) =...

Homework Statement Maybe, I am a little stupid, but I just can't understand what I am doing wrong here. I have 2 quantities which I have to convert to log (base 10) and perform a regression analysis. Quantity=1.235e9 error=3.4475e8 Homework Equations I have to express the above...

I have done a wind tunnel experiment on NACA 0015 airfoil for different angle of attack at a fixed velocity. Also calculated Cp, Cl, Cd and Cm for each angle of attack. Now I want to do an error analysis to find uncertainties in Cl,Cd and Cm. Please explain how I'm going to do that? I have...

Homework Statement The equation for the velocity of a falling parachutist can be computed by, v(t) = \frac{gm}{c}(1-e^{-(\frac{c}{m})t}) Use a first-order error analysis to estimate the error of v at t = 6, if g = 9.8 and m = 9.8, c = 12.5 plus or minus 1.5. Homework Equations...

Homework Statement Approximation of e^(x^2+3x+1) from 0 to 3 within .2 of the actual integral. Homework Equations Riemann Sum or Trapezoidal. (We haven't learned Taylor yet). The Attempt at a Solution Last n value i found was 148068 which gave me a delta x of 3/148068...im very...

Homework Statement I have used excel to make a linearized fit of data - x and y variables - with no problem. But I must solve for a value that can only be extracted from my slope, also not a problem. My problem is I don't know how to calculate the uncertainty for my slope, based on the...

Homework Statement Hi, I have this question that is bothering me. If I have a large set of data, each with its unique error uncertainty. How do I get the average error uncertainty from all the data points? Do I simply use the equation below: (∆ Z) ² = (∆A)² + (∆B)² And divide...

Not sure if this is the best place for this post, if it isn't any recommendations would be appreciated. My qustion concerns calculating the error from a set of radiation counts. I understand that the error in a single radiation count is \sqrt{N} where N is the number of counts. My question is...

Could someone please explain to me in fairly basic terms what the L2-norm is and what it does please. More specifically let me know what the following equation does, if possible... E(N) = 2*pi \int (U(N) - Uexact)2 r dr Where E is the error for a specific N. Ultimately I have values for an...

Homework Statement This comes from the data analysis of a lab on the Michelson Interferometer. d1={.208 mm, .275 mm, .214 mm, .214 mm, .230 mm, .230 mm} d2={1.757 mm, 1.505 mm, 1.725 mm, 1.773 mm, 1.640 mm, 1.732 mm} r=5.13945\pm.11981 \lambda\approx\lambda'=599\pm23.7\ nm Homework...

URGENT URGENT ... Error Analysis in angle Homework Statement This is very urgent i could not find out how to find the error in my angles... using calculus this is not my level but i must do it somehow.. i would love to see some steps that i can follow. i know that for example E = mgh...

Homework Statement d(theta)=1/sqrt(1-(o/h)^2) how would you differentaite the function of theta respect to o and h ? im very new to calculus, i would appretiate if someone giave me a very large step because im in a hurry to understand this and the sun is soon to rise please...

Homework Statement (i) Use Newton’s Method and apparent convergence to solve x ln(x) = 5 accurate to 3 and 4 significant figures. Start out with x0 = 2. (ii) Directly approximate the absolute error on f, i.e. _f = f(x) − f(˜x). (iii) Use the difference between the 4 significant figures...

Okay so I did a lab on Linear Motion using the glider with the air track and a spacer. This is the information I have about the glider and spacer. glider mass = (468.7 +/- 0.02) g thickness of spacer =(14.8 +/-0.05) mm I'm stuck on doing the error analysis and I don't know how to go on...

edit: Totally put this in the wrong forum on accident. Can it be moved to the Calculus and Beyond forum? Thanks. Homework Statement calculate the error associated with stress and strain Homework Equations First equation is stress, second equation is strain. P is load, A is...

I am a First year Physics Student going into Second Year in a few weeks. I've been coping very well with all the work and theory. However Along with tight and Limited Lab schedule my sessions feel rushed and unfurfilling, particularly the analysis section. Although we are given a lab manual...

Homework Statement I have a resistor which has value written as 5K\Omega and I measured the value and it is 4.8K\Omega. I want to work out the error. 2. The attempt at a solution I can use simple percentage calculation to get \frac{4800-5000}{5000} \times 100 = -4% error but I've been...

Homework Statement In my latest experiment, I have found two sets of data from the data processing. Normally, the values in the data sets should be equal, but they are not as a result of the error of the experiment. How can I do the error analysis? (Percentage Error, absolute error...)...

Homework Statement Hi, I've a lab assingment, and the labwork must be planned beforehand, but I have some trouble figuring out some parts of my error analysis. So, I'm supposed to measure (as in not use integrals to find out) the mass momentum of a ball. The plan is to place the ball on an...

Just a quick question about error analysis. Moles of Calcium ions in 10 mL = 6.0 x 10-4 ± 0.5 x 10^-5 mols I'm suppose to scale this number to Moles of Calcium ions in 250mL. So when I multiply by 25, do I multiply the error value as well? Or does it remain the same?

Hi, I am not sure if this is the right place to post a COMSOL question. If not I apologise, could you point me to the right place. I have a 3D geometry in COMSOL shape like a "T" where I want to model flow using navier stokes and a chemical diffusion using convection and diffusion. Both...

I have an error analysis question...I carried out a titration, and I have error for each measurement, but I then took the second derivative of the data and graphed it. The actual value I am reporting was estimated from the x-intercept of this graph. The curve was not fit to anything. How do I...

I am trying to work out the error in the gradient for a linear graph. I have worked out the the RMS error for the y-values, but since I am using excel to determine the graident of the graph I am a little unsure about how to work out the percentage error in my gradient from the RMS error. Am i...

Homework Statement The error part of my physics labs have been takin up a lot of time lately. Anyways, say I have 10 numbers for time measurements like 3.53 s, 5.32 s, 3.57 s, 4.89 s, 3.24 s, etc... and my reaction time is say +/- 0.20 s. I want to average these 10 values out but I have to...

hello everyone, I have a couple of questions from my astonomy course that are confusing me. 1. Which do you think would cause the larger error: a 10% error in "p" (period of orbit) or "a" (length of semi-major axis in units)? I would think that the "p" would produce the larger error, because...

Homework Statement I am trying to work out if there is an elegant way to do a line of best fit(straight) through a set of points (3) while taking into consideration their error bars? Clearly I'm looking for a piece of software that can do this. Obviously excel, etc can do a standard straight...

Homework Statement What is the error in calculating the y-component of the force created by a hanging mass (m=432.23g) at an angle of 28º? Take g=9.81m/s^2)Homework Equations Fg = mg The Attempt at a Solution Fg = mg = (0.43223kg +/- 0.000005kg)(9.81m/s +/- 0.05m/s) = (0.43223 +/-...

Homework Statement I have a physics lab due and need help finding a velocity vs time graph from a position vs time graph. I also need help finding the Mathematical error analysis from the data. here is the data for the position vs time graph time(sec) position (cm) 0.0000 0 0.4084 10...

given that a=(6.0+/-0.1) and b=(17.5+/-0.3) what is 2a^2 + b^2 i'm having so much trouble with this i think we first go (6.0+/-0.1)^2 then times it by 2, and add (17.5+/-0.3)^2...i tried this but couldn't get the right answer...what am i doing wrong? ...ANY help would be greatly...

1. A system of 7 objects each have one measurement taken of them. These measurements are to be compared with two theoretical models, which theoretical model does the data fit best?[br]The machine used to measure the values has an extremely small error, so the data gathered does not have...

[Urgent]On error analysis of my practical Homework Statement well, the aim of the practical is to calculate the speed of light using LED, oscilloscope and varying fiber optics cable. i have my results as follows : L /m t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 taverage 5.00 (28 30 28 28 28 28 28 28...

Hi, I'm investigating the variation of Magnetic Field with Distance. The investigation requires me to plot lnField against lnDistance. My question is, say the quantities had an error of +/- 0.01 mT for the Magnetic Field. How would I represent this on the ln Field v/s ln Distance graph? I...

i have 5 values of slit width S 0.0015m 0.0158m 0.00191m 0.0021m 0.00257m the standard error is plus or minus 0.0005 however my teacher says she wants us to calculate ∆S error she says its ∆S=S(subscript 2) - S(subscript 1) she says the answer is 0.0007m WHY IS THIS SO...

Here is a question I can not seem to get from an error analysis course. Assume that you have a box of resistors that have a gaussian distribution of resisances with mean value mu=100 ohm and standard deviation sigma=20 ohm (20%resistors). Suppose that you wish to form a subgroup of resistors...

This is my report on an experiment that I have done and I really needed the latex codes to generate the equations. I have done the other parts of the report on other PC. Do they seem to be ok? (the errors, like the max possible value and min possible value) no help is really needed, rather...

Any error analysis gurus out there? I'm trying to work out the uncertainty for the following equation: C = \sqrt{(A-B_A)(P-B_P)} A and P are counts from a radioactive source from two opposing detectors. B_P and B_A are background counts with no source present. It's a simple geometric...

In my BC calc class, we just finished working through most of series and sequences, and as we were reviewing years past free response questions on the topic, and in 2004, they dropped a lagrange error analysis. I've been looking at different explanations, but I'm not getting the concept. It...

I'm having a problem with something I know should be simple, but my answer is off so I'm doing something wrong. I need to find the amount of error for an acceleration that was found using the formula a=2d/t^2. Where d represents distance travelled. There is no uncertainty in the distance...