Measure Definition and 1000 Threads

I'm trying to find a certain type of scale that will measure the pressure I exert on it but I'm not really an expert on scales. I need one that will easily read the amount of pressure when I'm grabbing a counter or something and pulling my body weight down upon it. So I need one that can measure...

hi i want to find the output impedance of the following cct so i can perform pi matching on it but i don't know how to find it using lt spice please help! added schematic

Dear all, I am trying to understand something for SNR, I know that is the ratio of the Power of a signal divided by the Power of noise. According to wikipedia Signal-to-noise ratio is defined as the power ratio between a signal (meaningful information) and the background noise...

For this lab, I'm supposed to use materials that heat up but doesn't allow heat to transfer. I've used raw spaghetti noodles already but I still a few more for more trials. So what materials are good for this lab? after heating up the material, I measure the distance between the "hot spots" so...

Ok, so given two hypothetically identical systems (like two spaceships with identical mass, onboard matter, etc.) am I correct in thinking that if the two to accelerate to different speeds and fall back to the same speed, the one that was traveling faster will have experienced a lesser degree...

Homework Statement Suppose you know the wavelength of light passing through a Michelson interferometer with high accuracy. Describe how you could use the interferometer to measure the length of a small piece of material. 2. The attempt at a solution - Sandwich the piece of material behind...

Guys, I'm taking real analysis starting with open, close, compact sets, and neighborhoods. Now I'm addict to rely on these concepts to do my proofs. In the future I will have to take Measure Theory. Can anyone give me a percentage indication for how many percent theorems are proven by the set...

How could one measure degree of coherence with Fresnel biprism? Hello. I have some questions about the study of partial coherence with a Fresnel biprism. In common text degree of coherence and its relationship to visibility is introduced considering a Young Double Slit experiment. At the...

Can you give example of systems that self collapse? For example, is radioactive decay an example of self measurement? How about 13 billion years ago when stars were just being formed, is it an example of self measurement? Because I can't imagine how stars can form when all things are in...

Can anyone recommend a book(s) that covers these topics: Measure theory / lebesgue integration Hilbert Spaces Distributions PDE's The only material I have is the lecture notes and they are quite difficult to work through. I need to get the basics I think, before I will...

As the title says, I want to measure the angle of a street from true north so I can know what time of the year the sun will align with it.

Hello, I've read about this in four different textbooks and in several websites, but I still don't get it: how are Cepheids used to measure distances? I understand that Cepheids are stars whose brightness varies periodically; that the longer their period, the brighter they are; and that...

Hi all, I apologize now at how elementary this is, but I have been all over google and I cannot get a straight answer. My question seems to me be to be quite easy. Maybe I am over simplifying it. Anyways, any help is much appreciated. Btw, it's been 15 years since my last physics class...

If i have a measurable set with positive measure, how do I prove that there are 2 elements who's difference is in Q~{0} (aka a rational number that isn't 0.

My friend has a 24 HP electric generator and wants to know the number of watts being delivered. My understanding is that the 24 HP refers to the power input to the generator and he wants to know the output power generated. Can someone tell me how to measure it?

Hello, I would like to know what are the differents methods to measure the speed of the light. Thanks :smile:

A book I'm reading says: If a set A has infinitely many points which can be arranged in a sequence a_1,a_2,\cdots,, then A has measure zero. What does it mean by "can be arranged in a sequence"? The book gives an example on the set A which is all the rational numbers between 0 and 1. Why...

For that matter how do you detect the position of particle. Note that I am aware of HUD and therefore am asking you measure them sepretly.

how to measure perimeter without pi? [before they knew about the pi ratio]

Note: I have never formally studied number theory so what I'm about to ask may be either completely trivial or completely meaningless. In either case, I don't know what to search for to find my answer since I don't know the terminology. Is there a measure of how far from a prime a given...

I am a bit confused about what accelerometers actually measure and hopefully somebody can help me resolve the following scenario: Say we have a vehicle with mass m, fixed CG location and subject to gravity. The vehicle is traveling at constant speed in the X direction heading to a cliff...

Homework Statement Hi I need help with designing an apparatus to test my aim. Aim: Does the speeding up/slowing down of the rate of flow of water affect its electrical resistance. I need to create an apparatus in which I can alter the rate of flow of water and test the electrical...

Homework Statement http://meinprojekt.hostzi.com/images/Picture2.jpg We did an experiment to measure E mf or the cell voltage of bateries. A thin wire (slide-wire potentiometer) is connected into the circuit. From point a to c the resistance along the wire is 36 Ohm. Depending on where the...

Suppose that antiferromagnetic material have two sublattice. How can we measure magnetisation in sublattice A and in sublattice B? Maybe neutron scattering? How that work? Is NMR good solution maybe?

Can we really measure a physical property of something, without changing it in any way at all? In a circuit, you cannot use a voltmeter to measure a voltage without changing the circuit. The change may be small or negligible in most cases, but it is there. If you use a thermometer to measure...

Thought experiment. Let's imagine I'm on my spaceship moving in the void. For this example, I'm assuming my flight started on the Earth, where I could see the ground and landscape and thus I was able to tell that I was moving; however, without accelerating or decelerating, I progressively got...

Homework Statement I am trying to prove that if f is continuous almost everywhere on [a,b], and if g is cont a.e. on [c,d], with f[a,b] contained in [c,d], then g composite f is cont. a.e. The Attempt at a Solution ------ Originally, my proof went something like this: f is cont...

Homework Statement Let \mathcal{A} be σ-algebra over a set X, and μ a measure in \mathcal{A}. Let A_{n} \in \mathcal{A} with \sum_{n=1}^{\inf} \mu(A_{n})< \inf Show that this implies μ ({x \in X : x \in A_n for infinitely many n}) = 0 . The Attempt at a Solution I don't even see how is the...

hi, i am learing about measure theory and i am looking fore some good reference of the subjects ..

I'm going in circles on units (or perhaps more accurately different unit systems). The two my professor has chosen to work in are Gaussian units and MKSA units. My problem is one of lack of understanding; are the units of measure for electric and magnetic fields in these systems: Gaussian: E...

A few shopping centres in my area have these devices that can measure your weight and height. I figured I'd try it out, all you had to do was insert a $1 coin. Thing is, it has this type of tube on the top of it (the actual device was in an elongated C shape with a small platform to stand...

[b]1. x^-2dxdy and x^-1dxdy are left haar measure and right haar measure respectively how?

I saw this problem on this site a while back and started to think about it. I can't find the post so I'll start it anew. The problem is: can you have two disjoint sets dense on an interval so that the measure of each set on any interval of that interval is equal? That is, say you have A, B in...

We learned yesterday that a voltmeter's resistance approaches infinity. And that infinite resistance means total disconnect. I'm trying to understand why is that? Why must a voltmeter's resistance approach infinity? Doesn't it mean that the voltage will be 0? BTW - I hope I'm translating...

Dear Friends & Colleagues, I would like to propose the following Question, Is there a way to technically Measure the Gravitational Pull of a body? (body being any of the following: molecule, physical item like a rock, or a planet or a star). I am not looking for a sample of a falling...

Hi, everyone. I would to identify colors (fur colors, in this case, but I suppose that's not important) with greater precision that using color words, (eg. Rufus). Ideally, I'd use a spectrometer to find reflectance curves, but I don't have one, so I thought that using a digital camera...

Homework Statement Today I did an experiment to met the light intensity, a function of the wavelength of light. I gained a theoretical model *how it should look*, which had 1 light intensity peak at lambda=1083nm. On the other hand, I measured several peaks, 1 at ~600nm and another at ~750...

The double slit experiment is often described like this: (I'll describe the photon version, but of course the electron one is the same) "We fire individual photons at a screen with two slits. An interference pattern appears. But when we try to look at the slits to figure out which slit the...

Supposedly, you use a certain type of seismometer. But in that case, how could a deep earthquake far away register as "higher" than a shallow earthquake that's up close? Sure, the deep earthquake may release more energy, but much of it is dissipated by the time it reaches the seismometer (and...

We have a customer asking us for the thermal conductivity of a product we sell. None of the engineers have that number. I can think of a simple experiment that might do it, but I don't know the math. I want to take a piece of this material (it's a pipe), put a cap on the bottom, then...

Homework Statement Suppose f\in L^2[0,1] and \int_0^1f(x)x^n=0 for every n=0,1,2... Show that f = 0 almost everywhere. Homework Equations My friend hinted that he used the fact that continuous functions are dense in L^2[0,1], but I'm still stuck. The Attempt at a Solution I need...

Homework Statement Let A be the set of all rational numbers between 0 and 1. Show that for any "finite" collection of intervals I_n that cover A the following inequality holds: \sum I_n \geq 1 . Homework Equations We are using the definition of the outer measure here. Where the outer...

Homework Statement \mathcal{A} is a \sigma-algebra, A_n,A\in\mathcal{A}. Prove that if A_n\uparrow A in \mathcal{A} (i.e., A_1\subseteq A_2 \subseteq ... and \bigcup_{n=1}^\infty A_n = A), then \mu (A_n) \uparrow \mu (A)The Attempt at a Solution The up-arrow notation is defined on these sets...

I got to measure the diameter of a marble with a micrometer. Whatever the diameter and the radius be, it doesn't matter here and calculate the volume of the marble I was told to use the formula " V = Square root of (4/3 * 22.7 * rcube)". Then the last question was asked: "Give 1 practical...

Hello, I am preparing for a screening exam and I'm trying to figure out some old problems that I have been given. Given: Suppose \mu is a finite Borel measure on R, and define f(x)=\int\frac{d\mu(y)}{\sqrt{\left|x-y\right|}} Prove f(x) is finite almost everywhere If I integrate I...

Homework Statement The problem is Excercise 5. in page 88 of Folland's "real analysis: modern techniques and their applications", 2nd edition, as the image below shows. Homework Equations As the hint indicates, we should use Excercise 4. The Attempt at a Solution From Excercise 4, if...

For my Advanced Higher Physics Investigation i am measuring acceleration due to gravity. Having already done it with a simple pendulum my teacher says i have to do the same with a "Compound Pendulum". I was wondering how to do this and also how to make a compound pendulum with a steel rod...

let f_n be series of borel functions. Explain why set B = {x: \sum_n f_n(x) is not convergent} is borel set. Proof, that if\int_R |F_n|dY \leq 1/n^2 for every n then Y(B) = 0.Y is lebesgue measure.for first part i thought that set of A={x: convergent} is borel, and B=X\A so it's also borel...

A set E subset of real numbers has measure zero. Set A={x2 : x\inE}. How to prove that set A has measure zero? (E could be any unbounded subset of R)

Homework Statement The question is from Stein, "Analysis 2", Chapter 1, Problem 5: Suppose E is measurable with m(E) < ∞, and E = E1 ∪ E2, E1 ∩ E2 = ∅. Prove: a) If m(E) = m∗(E1) + m∗(E2), then E1 and E2 are measurable. b) In particular, if E ⊂ Q, where Q is a finite cube, then...