Measurements Definition and 382 Threads

Greetings fellow members, I have some queries on a laughably rudimental topic regarding measurements. Say you have a metre rule with sensitivity of 0.1cm, and you are measuring a wire which stretches from the 0.0cm starting point to the middle point between 7.3 cm and 7.4cm. My...

Measure phase and line voltages. Measure currents in the three lines and neutral. Measure total power dissipated in the load. Calculate total apparent power absorbed by the load. Determine power factor. Draw phasor showing voltages and currents.P=P1 + P2 Q = √3(P2 - P1) |S| = √(P2+Q2) θ =...

Hi, During my internship I worked with an Ellipsometer. Now I'm wondering, what values of Psi and Delta do you get when you measure a mirror under an Ellipsometer? Are there any phaseshifts at all? Because there are no layers on the mirror right? It's fully reflective in total.. Hanna

Homework Statement The experiment set up is a steel ball bearing is held from an electromagnet and above a switch at the bottom. When the electromagnet is switched off a timer starts and stops when it hits the switch. The height from the bearings initial position to the switch is measured...

Hi everyone and happy New Year. The Standard Model shows very specific and measurable couplings of the Higgs boson with the W and Z fields. What QUANTITATIVE measurements have been done to verify that these couplings are as predicted? Thanks and looking forward to your replies. A lot of...

I need to drag and drop all the labels into the relevant boxes by the bar chart. Three spaces will be left empty because there is anything to describe them. (See the attachment) I was thinking: title empty empty smalles difference between ... empty independent variable dependent variable...

Hi, I am in the middle of a project dealing with the mass loss rate of protostars and hence I am working with the distance that these sources are away from us. I need to find the error in these distance measurements, however I cannot. In any paper (I find) that cites distances it just gives...

Hello, I believe this to be a rather simple problem but I am not quite sure if my thinking is correct. We have a particle in a j=1 state of angular momentum J. I am first asked to find some eigenvectors of the matrix J(y): J_{y}=\frac{\hbar}{\sqrt{2}i}\begin{pmatrix} 0 & -1 & 0\\ 1 & 0...

Hai, I am doing my masters degree in physics. can somebody help me in which formula to use for calculating resistivity of a sample of circular shape using two probe measurements, which should include thickness and correction factor also. Thank You!

I'm looking for some good quality books on experimental methods, instruments, and measurements for graduate level. Do you guys have any recommendations?

We used a wheatstone bridge, which is an electric circuit consisting of four resistors.Two of the resistors are known, one resistor is a large "resistor" with dials that control the resistance, and the fourth resistor can either be a metal or semiconductor. The metal was heated to about 290 °C...

Hi everyone, I know this topic has been discussed quite a bit -- and in particular it's been done in this thread and this thread. But there are still some things I want to talk about in order to (hopefully) clarify my own thoughts. One of the threads discusses this Ballentine article in which...

Homework Statement The z-component of the spin of an electron is measure and the value h-bar/2 is found. Immediately afterwards, the spin along a direction making an angle θ with the z-axis is measured. What are the possible outcomes of this second measurement and with which probabilities do...

Here's what I understand... Types of errors 1.Systematic errors Zero Error errors due to slow stopwatches errors due to incorrectly graduated scales 2.Random errors error due to unevenness of the measuring item parallax error Ways of comparing errors Absolute...

I have the equation E(t)=7*sin(11000t+∏/3) and I measured the following: E(.22ms) = .422V Frequency = 1.751kHz Period = 572.0 μs Peak = 7V Peak-Peak = 14V E(rms) = 4.8V E(average) = 105mV I've calculated the following to compare E(.22ms) = .422V Frequecy = 1.75 kHz Period...

Bohm trajectories and "protective" measurements? I'm having trouble understanding the arguments presented in these papers. They seem to be both arguing against the de Broglie-Bohm theory bassed on the concept of "protective measurements". Is this just a rehash of the problems with the meaning...

1. Why did Aristarchus make his measurements of the Sun's distance at the time of the half moon? Aristarchus watched for the phase of the Moon when it was exactly half full, with the Sun still visible in the sky. Then the sunlight must be falling on the Moon at right angles to his line of...

I have read a few papers that were written in the early 1900's where their concentration measurements are M/4, M/8, M/16, M/32, M/256. I am not sure what this means and I was wondering if anyone could relate these concentration measurements to normal concentration measurements we use now, such...

I'm trying to determine the XY coordinates of 3 corner points of a quadrilateral shape based on known lengths of the sides of that shape. I know the lengths of all 4 sides of the shape as well as the lengths of both cross lengths (effectively making two adjacent triangles). I've attached a...

I work for a drug company & they have a department of Metrology - "Metrology is the science of measurement. Metrology includes all theoretical and practical aspects of measurement." Anyways, so what exactly are the theoretical aspects of measurement? To me, they would be something like...

Hi, it's my first post here, though I've long viewed these forums without a registered account. I was thinking about gravitational waves, and what exactly they would do. From what I understand, these waves affect everything with mass in the universe. The force they exert is exponentially...

Hello! I have a question regarding measurement uncertainties. This is not a homework problem. Let's say that I want to measure some quantity, and I want to measure it multiple times using multiple identical but separate instruments. That is, -First measurement taken using equipment 'A'...

Hi all! First off: I don't know which forum to post this. I'm no grad student or PHD so academic forum seemed wrong, and it's not really just math, since it was the result of a measurment and the signals can come from environment, etc. Ok. I measured the magnetic field using a sensor...

Okay, I tend to have some weird thoughts, so bear with my odd question here. Suppose you have a collection of particles that obey Newtonian mechanics. For simplification, all particles are identical and can be assumed to be hard spheres that collide elastically. Each particle has a position...

How are measurements done in the Doppler Orbitography Radiopositioning integrated by satellite.Please tell in detail.Or books related to it.

Hello. I have been going through some old OU books on the sciences and started working through an excercise when I came to a stumbling block. I have come here in the hope that someone may be able to shed some light on my problem. This is all for personal study as I am not enrolled on any...

Dear all, I have a specification from a tool, which says, 80% of the reported measurements are within plus or minus 10% of the actual, at 95% confidence level. I am trying to make sense out of this statement. Assuming a normal distribution, please can someone tell me how to interpret...

I've been looking up some information regarding the Owl Nebula, in order to make some calculations of my own. I've only been able to find the V magnitude or the general magnitude of the nebula as a whole. Is there any way to find the B magnitude or the B-V measurement of the star, given what...

In entanglement swapping: If we detect photons 2 and 3 in the following states |135>|45> or |45>|135> (accompanied by the appropriate coincidence counts), do we project photons 1 and 4 into the same bell-state (so photons 1 and 4 are also found in either |135>|45> or |45>|135>)? How would...

I'm struggling to figure out whether measurements of the second kind can be treated using the unitary ansatz. as far as I can gather Von Neumann's measurements of the first kind can be modeled as below: for system being measured S and apparatus A with states |S1>, |S2> and |A1>, |A2>...

Hi, I was trying to measure DC link current on a switched mode power supply when I came across a quirk of my circuit. I'm using an LEM HX 03-p SP2 hall effect current transducer to measure current. I couple the output node of my current transducer to ground via a 2KΩ resistor. The device's...

Dear forum users, I have a quite simple question. I have got a flux of protons measured in 1/(cm^2 s sr), I would like to have it in 1/(cm^2 s). nykon

Hello everyone. I wanted to know if, for low wing single engine nose-driven prop aircrafts, there has ever been a measurement done, while in flight, of the actual amount of wing bending occurring during sustained level turns at a measured G force, including full power sustained turns...

Consider an experiment in which a closed box is set up with a system inside that is initialised at time t=0 with state psi(0). A measurement of quantity w of the box’s contents is made at time T, that is observed by scientist S1. There is another scientist S2 that can, by pressing a button...

Homework Statement "Some people say stirring a hot liquid with a thermometer gives a better measurement and some say it yields a worse measurement. Explain with physics how one is actually better" Homework Equations None that I know of. The Attempt at a Solution I know that...

Homework Statement Supposedly, I put an object on a scale inside the elevator of a building, the scale reads m1. I start the elevator to the top of the building, during acceleration, the scale reads m2. As the elevator normalized, the scale reads m1. During the deceleration at the top, the...

http://cosmos.lbl.gov/two_four_maps.html http://cosmos.lbl.gov/Images/phys_today_cover_big.gif CMBR dipole anisotropyFrom the CMB data it is seen that our local group of galaxies (the galactic cluster that includes the Solar System's Milky Way Galaxy) appears to be moving at 627±22 km/s...

As far as I know all light speed measurements done using light sources that utilized electrons. The nominal light speed measurement used laser which is actually exited electrons. The speed of X-ray radiation from synchrotron used accelerated electrons. The speed of gamma radiation also involved...

Not sure where this one should go, please move if this is the wrong forum: There is a verse in the Christian Bible where a bowl is described to have the following dimensions: 10 cubit diameter 30 cubit circumference 1 Handsbreadth thickness A modern cubit is 18 inches, 1...

Homework Statement Why are mammals as large as they are and not much larger? Homework Equations Two figures are given. One of the mammal with size S and mass M. Femur is the thigh bone of the mammal with l being the length of the femur, d being the thickness of the femur and A being the...

Homework Statement Currently, I'm expected to find the side length of a square garden whose area is 25cm2. Of course, we're talking about a square here, and since the area of a rectangle is l * w, and, when talking about a square, l = w, the area of a square is S2. Of course, I know each side...

Homework Statement During heavy rain, a section of a mountainside measuring 3.6 km horizontally, 0.53 km up along the slope, and 1.1 m deep slips into a valley in a mud slide. Assume that the mud ends up uniformly distributed over a surface area of the valley measuring 1.2 km x 1.2 km and that...

Say we have a stream of particles, emitted from a source, traveling freely in one direction and then colliding with some sort of screen. Between the source and the screen the particles are said to be in that indefinite state of limbo known as coherent superposition. Do the particles in this...

Hello everybody, I'm working on a project and I want to verify a few theories I have. I'm unfamiliar with equipment for taking these types of measurements, so I wanted a little bit of help on this. Basically a bb is fired from an airsoft gun (350-550 fps), and I want to find the...

Homework Statement Neutrinos are created in states of one of two possible flavors, f_1 or f_2. Each flavor state can be expressed as a linear combination of mass eigenstates with masses m_1 and m_2 |f_1\rangle = |m_1\rangle a_{11}+|m_2\rangle a_{21} |f_2\rangle = |m_1\rangle a_{12} +...

Entanglement – the order of measurements can be important. I try now with some formulas - hope it's reasonably understandable: First known substance - unless I am floundering in it: I imagine that the p - photons is measured first (p1) and meets a PBS (0) (x = horizontal and y = vertical)...

I'm trying to measure inrush current by looking at the voltage of a 0.1ohm resistor in the line within the first 50uS of flipping a relay to a variable AC source. Problem is that the new AC source that I have (chroma 61605) apparently has an impedance issue which prohibits good inrush...

I have read on some threads that there are other possible shapes for spacetime and I wondered could any of these spacetime shapes, or their change over time, affect our measurement of red shift? Also does the matter density at the location where a photon is emitted relative to our own...

Homework Statement The radius of a circle is measured to be 2.4 cm +/- 0.1 cm. Find the error in the area of the circle. Find the error in the circumference. Homework Equations Have no idea but I'm taking a guess it could be multiplying fractional uncertainties? The Attempt at a...

Hello all, Recently one of the power meters on one of our office's panelboards has been giving sensor garbage, calling the others' measurements into question. I have two 277/480Y transformers, one going to a two phase 480V duct heater and one going to the lighting (the meter reads three...