Accuracy Definition and 224 Threads

I ran into an issue on a project where I'm needing to be sure of the accuracy of airflow measurements being taken. There are two basic ways to measure the airflow of an air conditioning system: 1. First is to traverse the main supply duct with a pito-static tube array and a differential...

This was part of a lab i preformed to determine rate law for HCl and Mg. 50 mL of 0.5M, 1M, 1.5M and 2M HCl solutions were made using water and this was used with Mg ribbon to find the rate law. The same 0.5M, 1M, 1.5M, 2M HCl solutions were made in 100mL solution that contained water. I was...

An experiment was done by me to determine the rate law of a reactant. If the reaction occurred faster(ex. by just stirring reactants), would the accuracy of rate law calculated increase? If it doesn't increase accuracy, then what is the point of stirring/swirling the reactants? I think that...

http://img718.imageshack.us/img718/2489/asteroidtiming.jpg Here is a scene of a star destroyer firing on an asteroid. The entire explosion takes about 10 frames of video -- less than a third of a second. It's widely believed that the asteroid in question is about 40 meters in diameter and...

Homework Statement So, I'm creating a 2d graphical simulation of orbiting bodies. Right now I'm just working with 2 bodies, one stationary, but I would hope to extend this program to be able to include any number of moving bodies and have them interact accordingly. After combing...

Homework Statement Any problem. Ex Use the Mac series of tan^{-1}\left(x\right) to approximate at x=\frac{1}{2} to three decimal place accuracy. Homework Equations \sum^{\infty}_{k=0}(-1)^{k}\frac{x^{2k+1}}{2k+1}=x-\frac{x^3}{3}+\frac{x^5}{5}-...The Attempt at a Solution I found out using...

Anyone know what a typical clock skew would be on your average PC these days? Updating my clock with NTP it appears my laptop (when running 24h and not in idle mode) drifts about 2 seconds a day. I get the impression that's a lot. (John Harrison was building better mechanical clocks 250 years...

Hi guys, i was given a project based on the above topic and i know very little on it. Can anyone help to explain what's the difference between MSE and therotical MSE. Taylor series estimation and the modified taylor series. Thanks

Homework Statement Show that the series is convergent. How many terms of the series do we need to add in order to find the sum to the indicated accuracy? \sum^{\infty}_{n=1}\frac{(-1)^{n}}{n*9^{n}} (|error| < 0.0001) Homework Equations Alternating Series Test General knowledge of adding...

Hi Everyone, I've been trying to find a load cell for a report and I need one with a maximum capacity of >200Kg and and accuracy of 10 grams or better (used in compression). I've taken a look on the web and the highest accuracy I can find is about 0.03% of the maximum capacity; which with a...

Hi Can anyone help me to solve the following question; Note: in both equations the +/- is written above and below of each other without the '/' sign. Thanks.

I was grading my labs and in this lab, we used a meter stick and a wooden protractor. A group finally wrote in their write up that they believed the error was due to the inaccurate nature of the equipment. This begs the question, what sort of tolerances do you see in the manufacture a typical...

Is there a general approach to calculating the impact outliers have on the accuracy of one's (predictive) model?

Homework Statement GPS can be used to determine positions with great accuracy. The system works by determining the distance between the observer and each of the several satellites orbiting Earth. If one of the satellites is at a distance of 20,000 km from you, what percent accuracy in the...

Homework Statement Estimate the minimum length of time needed to measure the energy of a photon to an accuracy of 10^(-15) Joules. Homework Equations E = hv, where v is the frequency of the photon and h is Planck's constant in J*s Watts = Joules/second The Attempt at a Solution...

I wonder whether the accuracy of that thermometer with a type K sensor is as follow: encironment: 90'C Sensor type: resistance sensor so the accuracy = +/- 90*0.005+0.5 = +/-0.95'C Thanks for your help.

This is either a topic that is so blatantly obvious that it's ridiculous I'm saying it, or I'm missing something. From my limited physics knowledge, I know that absolute zero is a temperature in which the molecules are not moving whatsoever. In other words, it's the lowest possible...

Use taylor's THeorem to determine the accuracy of the approximation: cos(.3) ~=1 - (.3)^2 / 2! + (.3)^4 / 4! when i use taylors theorem, i use (.3)^4 / 4! which gets me 2.03e-10 but the asnwer is R<=2.03e-5

So, as the title says... - What is an acceptable spec? We're not talking in seconds per year or anything like that. Does anyone know a rough industry standard? - This hourmeter will be designed into a machine that will accumulate a couple thousand hours a year max. A .2% accuracy will...

[SIZE="6"]Please explain uncertainty and give examples like i know it is 'half the smallest degree' just not suree.

How do we show that the greatest accuracy in the |mn> state is |n| = m for the Mx and My components?

Hi I have done my experiment by using an Oscilloscope, (10 k ohm) resistor and 220 nF capacitor and a probe to find the the V out and then finding Gain and phase shift, my question is what's going to affect the accuracy of the data being received from the experiment results?

Homework Statement A gun is aimed directly at a can, which is simultaneously released when the gun is fired. This gun won't miss as long as the initial speed of the bullet is sufficient to reach the falling target before the target hits the floor. Verify this statement. Homework...

How many terms of the series do we need to add in order to find the sum to the indicated accuracy? The alternating series from n=1 to infinity of ((-1)^(n+1))/(n^2) |error| less than 0.0399 i got it down to 1/n^2 is less than 0.0399 but i can't figure out if n = 5 or n=6... please help:(

Homework Statement The oscillation period of a torsion oscillation magnetometer of T=3s can be measured with an accuracy of 1µs. Let the moment of inertia of the sample and holder have a value of J=10-6kgm2. Evaluate the accuracy with which a small magnetic moment can be determined...

I know that σ is the symbol typically used for standard deviation, but what does the use of σ mean in these contexts? ex. 1: "[our fancy new instrument] ... allows for the identification of > 500 sources at greater than 10-sigma" ex. 2: "These estimates assume ... a 1σ polarization...

Can anyone please tell me which one of the following is the most accurate method of Volume measurement for 6 mL of water (density= 1g/mL): Graduated Cylinder, Pipet, or Buret. Also, how can you explain your answer. Every help would be appreciated.

I have been curious about this for a while... I'm interested to know if there is any easy way to tell the accuracy of the (n+1)th on the nth term of the Fibonacci series in relation to the golden ratio. I know that as n tends to infinity the ratio tends to the Golden Ratio "Phi" - but is...

Hi, does anyone know what sort of methods I could use to test the accuracy of the numerical solution of the integral equation? Many thanks

In general, are the measurements of current or voltage more accurate? From our lab experiments, it seems that voltage is more accurate. I'm curious as to why this is the case. My guess is that because current itself is the measurement of the flow of the electric charges it would be more...

I am working on a lab and I need to know the accuacy of gravity=-9.8m/s/s? So I need the +- blank after the -9.8m/s/s. -9.8m/s/s +- _________m/s/s Thank you Stephen Doty

I need help making my basic arithmetic more accurate. [eg. 2*2=4] If anyone has any suggestions they are greatly appreciated. The Attempt at a Solution I tried some online games but they don't help very much. Is it really just practice practice practice?

From the facts that 1150 = P0exp(2 k) and 11500 = P0exp(8 k) we can solve for k and P0. Provide at least five decimal places of accuracy for k and at least two decimal places of accuracy for P0. I've got P0 = 1150/e^2k and P0 = 11500/e^8k but when i try to solve for any variable by...

We have measures that define the volt, amp, kilo, pressure, etc, etc, compared to these measures how accurate are red shift figures? i know that tolerances are only guaranteed in a machine shop if the temperature is within limits, and all the above can be tested time and time again, but how...

What is the difference between accuracy of a measurement and its level of accuracy? Is the level of accuracy quantitative or a qualitative measure?

hey, can somebody please help me examine the truth of the statement "the moon moves in a near-circular orbit around earth. because the Earth is so much more massive, it own motion is not appreciably affected by the moons presence" ?

Does the Simpson's rule of numerical integration (\frac{1}{3}h\left( {f_0 + 4f_1 + f_2 } \right)) give exact values for all polynomials to a third degree i.e., linear functions, quadratic functions, and cubic functions? Is there a better method for numerical integration approximation? One...

How can iq tests be accurate if people can come up with multiple logical answers to a single question?

If an electromechanical instrument's (say a galvanometer) accuracy is given as a percentage of its full scale deflection, what would its accuracy be at anything lower than full scale deflection? My thoughts: If say full scale deflection is 100V The error is +-1% which is +-1V, Does that...

Anyone got any experience? Don't need anything with the accuracy of a CRT oscilloscope but ease of setup, repeatability, portability and convenience are more important.

Hi everone, Really stuck on this one, if anyone has any suggestions I would be more than greatful! Problem: A HIV test detects at 90% accuracy It falsly detects people as positive without HIV at 2% and it is estimated that 50% of the tested patients have HIV I need to work out the...

Ok. I'm fairly new so go easy on me. I apologise if this is posted in the wrong section. Can someone point me in the right direction of being able to work out samples of a web poll. A web poll I did returned the following results for a sample of 40 people and spending habits of a...

Hi. I was wondering if it's possible to calculate bullet accuracy in terms of percentage in a series of ranges, given bullet's max effective range, a series of ranges, bullet mass and velocity with gravity (assuming no wind resistance, or any frictional resistance). I'm looking for a...

Homework Statement The planned Gaia satellite is a successor to Hipparcos. It will have an astrometric accuracy of 24 micro-arcseconds, and be able to detect Cepheid variable stars in the Magellanic clouds (~ 70kpc away). Estimate how accurately Gaia will determine distances to these...

I've got nine sets of data (three people each took ten measurements of three different distances), and I need to find an estimate of the accuracy to which each person measured each distance. I've already calculated the mean and standard deviation for each set of data, but I don't know how to...

Hello everyone--first post--thank you for having me this seems like an awesome place :biggrin: I'm not totally sure where to post this since it's a general problem solving question but basically I want to be able to solve physics and math problems in a shorter period of time. Aside from the...

We did an experiment with abysmal accuracy. I'm now writing up my report and would like to meaningfully express the error between calculated and measured values. EXAMPLE calculated T=0.284 measured T = 0.201 I want to express the difference between them as follows: % difference...

Hi, I have a function f(x) = \frac{\cos(x^2)+x}{x^2+2},\quad x\in[0,3] I have to find the extreme values of the function in in the range [0,3], with Maple, by solving f'(x) = 0. Maple will solve these numerical, and I get 3 values. c_1 = 0.5345058769, c_2=1.732313261 and c_3=2.461303848 ...

Hello, I'm trying to decide how I will provide excitation voltage to the wheatstone bridge of a load cell. The output of the load cell will be amplified by an LT1167 In-Amp. How concerned should I be about the precision/accuracy of the excitation voltage? Since the In-Amp will reject common...

I have a few questions regarding measuring devices in systems such as ventilation, heating, cooling etc. When calibrating these I come across the terms "accuracy" and "resolution" (directly translated from norwegian). I a bit confused about the difference of these. Can someone explain this to me...?