What is Uncertainties: Definition and 167 Discussions
In metrology, measurement uncertainty is the expression of the statistical dispersion of the values attributed to a measured quantity. All measurements are subject to uncertainty and a measurement result is complete only when it is accompanied by a statement of the associated uncertainty, such as the standard deviation. By international agreement, this uncertainty has a probabilistic basis and reflects incomplete knowledge of the quantity value. It is a non-negative parameter.The measurement uncertainty is often taken as the standard deviation of a state-of-knowledge probability distribution over the possible values that could be attributed to a measured quantity. Relative uncertainty is the measurement uncertainty relative to the magnitude of a particular single choice for the value for the measured quantity, when this choice is nonzero. This particular single choice is usually called the measured value, which may be optimal in some well-defined sense (e.g., a mean, median, or mode). Thus, the relative measurement uncertainty is the measurement uncertainty divided by the absolute value of the measured value, when the measured value is not zero.
Homework Statement
Given that f=\frac{\bar u \bar v}{\bar u +\bar v}
show that
e_f=f^2({\frac{e_u}{\bar u^2} + \frac{e_v}{\bar v^2})
where e refers to the error. ok so I added up the fractional uncertainties
Homework Equations
The Attempt at a Solution
and I got this...
Homework Statement
Hi everyone, I'm having some homework trouble, and am hoping you can help me out. Here's the question.
QUESTION: Using the propagation method for calculating uncertainties, calculate the absolute, relative, and percentage uncertainty for the volume of the cylinder and the...
(First post. Go easy on me, mods :D)
EDIT: Seems I got the wrong forum. If a mod could be so kind to move it, I'd appreciate it :P
Hi everyone!
I'm working on a formal lab report for my physics class, and after propagating my uncertainties into a formula, I got an even smaller uncertainty...
Homework Statement
So basically I'm supposed to calculate final velocity given time, displacement, and initial velocity. The only problem is that I'm supposed to find these results with uncertainties included. I know the how to do basic calculations with uncertainties I'm just confused when...
Homework Statement
Basically I'm doing a lab and it states that I am not to omit uncertainties from my calculations. It has been ages since I've calculated with uncertainties so when I went back to my notes, they weren't there! Now I am completely lost and clueless. I know there are such...
Hello, first of all sorry for my bad english it is not my mother tongue
I am new to the uncertainty and significant figures concept and I have measured some things, I want to write the results using them.
The length of my table is 273,3 cm. The instrumental uncertainty is ± 0,3 cm, and I...
i need to know the formula for calculating the uncertainty of a gradient from a graph. the gradient is being used to calculate the moment of inertia but i can't calculate the error in my I cause i don't know how to calculate the error in my M!
when i did the experiment, i assumed the error to...
I've been studying absolute uncertainties and do not understand any of it. If someone can explain it will really help. Especially with uncertainties including diameters and area.
For the following calculation, would the uncertainty propagate as I have estimated?
\frac{\left(a \pm \Delta a \right) + \left(b \pm \Delta b \right)}{\left(c \pm \Delta c \right) \cdot \left(d \pm \Delta d \right)} = \frac{a+b}{cd} \pm \frac{a+b}{cd} \left( \frac{\Delta a + \Delta b}{a +...
Homework Statement
If the uncertainty in a measurement of dameter is +-0.02cm is the uncertainty in radius the same or half of this value. The formula given in wikipedia implies that it would be half of the value.
Cheers
Homework Equations
The Attempt at a Solution
My problem in short:
I have a set of data, and I want to calculate the linear regression, and the uncertainty of the slope of the linear regression line, based on the uncertainties of the variables
My problem in detail:
My data is from an experiment and the uncertainties (errors) are...
If an average of three numbers with equal uncertainties is taken, does the average have an uncertainty of the sum of the absolute uncertainties of the three numbers?
e.g. (3.0 +/- 0.1) + (6.0 +/- 0.1) + (9.0 +/- 0.1)/3 = 6.0 +/- 0.3?
This makes sense to me because the three in the denominator...
I need to determine the propagation uncertainty of a calculated quantity (function of the variables mass, acceleration due to gravity, cap plate separation, and voltage), but I do not know the uncertainties of these measurements. I just know the values. What should I take the uncertainty to...
I'm so confused of the Heisenberg's Uncertainties...
Here's a question i have to solve, although it looks very easy but my understanding of Heisenberg's Uncertainties is still shallow.
Fuzzy a quantum mechanical duck lives in a world which h = 2 PI Js. Fuzzy has a mass of 2.0 kg and...
Hi guys, i am trying to work out the uncertainty of this equation
Y = (AC-CX)/(B+X)
and i am needed to work out the uncertainty in Y.
values for these are:
Y=2.18 UNCERTAINTY UNKNOWN
A=29m Uncertainty in A denoted (Sa)=3mm
B=710mm Uncertainty in B denoted(Sb)=3mm...
A quick question about uncertainties and significant figures:
Say, we have some numbers with a particular uncertainty 0.1 of each of them. What happens if the sum of these numbers has a greater amount of significant figures than each of the numbers alone? For instance,
1.01 + 9.99 = 11.0...
I am trying to find F, i have L = 60cm and U = 31cm, how would i calculate f (focal length)?
and also how would i find the uncertainties?
thank you very much