Measuring Definition and 962 Threads

Hi, how is the speed of light measured in objects such as water, glass, diamond etc ? what are the tools and techniques used. thanks in advance !

This is a (fairly basic) lemma without proof I saw in a research paper. Wasn't sure how to classify it exactly, but decided it's closest to vector (and linear) algebra. It goes like this, consider a quadrilateral in the plane with vertices A, B, C, D in clockwise order. It is given that...

Is it possible to use a balance to measure the mass of a gas? Let's say that the experiment I'm going to describe is possible and takes place in a vacuum so as to avoid any buoyant force from the surrounding atmosphere, and the balloon to be used does not allow any effusion of the gas from...

I need to devise a way to measure the torque of a Rotating Motor. Now i already have 2 ways in mind but both of them require that the motor [SIZE="4"]stops while still being powered by a battery or something. ( I think we risk permanent damage to the motor ) Can someone point me to a...

Hello there, I'm an undergrad in my 3rd year and I'm doing an investigation into the 'Preparation of Thin Films and their use in Hall Effect measurements.' We are making thin films of bismuth on glass (with pre drilled terminals) in a vacuum system. The way they suggest measuring the...

Homework Statement well have this little problem for home work, I am to find out how to measure the preasure on the human leg or in my case a mecanic leg. there are different preasure oints as I understand it, with the foot. what I need to find out is what formulas would be used to both make...

Now here is a real world practical application. Australia Post has a warning for shipping magnetic material in the post. Section D2.9.2 states... Any material that, when packed, has a magnetic flux density of 0.159 A/m or more at a distance of 2.1 meters from any point on the surface on the...

Hello, I am new to this forum (and no physics expert). I apologize if this topic is in the wrong place, but I would really appreciate help on the abovementioned topic. I am investigating the effect of temperature on the capacitance of capacitors for a school project. Since C =...

Homework Statement I have tried to solve the displacement sideways of an lightray through a medium with snells law. The question is how much does the ray travel in x-direction in the new medium with width D. It says in the text that one should use pytagoras but I can't seem to understand...

In double slit experiment, what if we put a detector on one slit, instead of both slits. Does the interference pattern appear or not? I think, if superposition principle is true and particles passing through both slits at the same time, measuring one slit will be enough to collapse its wave...

Locally, Fermi normal coordinates are designed to correspond with direct measurement of distances (born rigidity). I also discovered that Synge's book on GR establishes that very locally, radar distance must match Fermi normal distance, but not in general (obviously). What I am wondering is...

In many equations, I see the term E, but I'm really confused on how exactly I can calculate this value. So if I were to an experiment and I needed to find the polarization density, and I needed the E value, where can I find it? Thanks :D

I was given the assignment to measure the parabolas of a suspension bridge. I have some ideas for how to go about it, like using a point of reference and going out from there. I was wondering if anyone had any other ideas. Thanks! Alex

Homework Statement Consider a particle-in-a-box problem, involving a particle of mass m subject to a potential: V(x) = +∞ for X≤0 V(x) = 0 for 0<X<L V(x) = +∞ for X≥L |ϕn> are the eigenstates of the Hamiltonian H with the corresponding eigenvalues: En = (n^2)*(hbar^2)*(Pi^2) / 2mL^2...

Hi, This is my first post on this forum, just joined. I recently purched the S3 Spyder III Arctic portable 1W laser from wickedlasers. I bought it to try and make some cool photographs and photoshop them. After testing the device (glad I bought safety goggles with it) I was wondering how hot...

Homework Statement A mass m is connected to a spring of spring constant k. The equilibrium position is x = 0 and the motion of the mass m is restricted by a stop such that spring compression is not allowed, i.e., x < 0 is forbidden . The system is in the ground state. (a) The stop is...

Hi, I was wondering how I would find the speed decay of a ball rolling in a straight line, if i were to measure the time it takes to travel a certain distance over and over. i.e [FONT="Courier New"] >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> <---10cm--> <---10cm--> <---10cm--> ^...

I'm trying to help my 6th grader measure and graph the amount of power (eg voltage) her hamster will put out running all night long on it's wheel that is connected to a small DC generator. I am hoping to not buy an expensive DAQ and software. Does anyone have any ideas how I can do this on...

I am very interested in physics but have no background education on it so forgive me if this question is amateur. I am trying to grasp this redshift thing. It's the measurement of a shift in the wavelength of light. The only variable I can think of is the wavelength of the light received on...

Am reading the attached labscript. Finding it difficult to understand at places. Any good sources of further explanation on the Net or textbooks?

Suppose there is a quantity X to be measured. To do this you have a measuring device with a resolution of 1 and an accuracy of +/-1. It is imediately obvious that repeated measurements can yield an accuracy of +/- 0.5 but can any greater certainty be achieved? If 2 measurements are made and...

first off I'd like say thanks to everyone on here, I've lurked and solved many questions thanks to you guys. First post woo. Basically we were tasked to design and carryout a lab to measure the coefficients of friction between a wooden board and some random objects (teachers gone for a few...

Hi all, Im currently working on a project that requires me to continuously measure the density and thickness of a sheet during an extrusion Styrofoam process. I have researched sensors and have found some that will do the job but of course they are in the $10k range. These however only...

Howdy Yall, First time poster, long time lurker. I am working on a project right now measuring the "useful" life of a battery...say a AA battery. To relate that to a real world application, I will be powering a light (LED) off the battery. I was initially planning on getting the battery, an...

Hi there. I was recently working out some expressions in Electro-Dynamics, to calculate reflexion and transmission coefficients. Ok, I reach some Fresnel equations. However, real materials are not so perfect, in sense that they are perfect surfaces, with perfect everything. So, I wonder how...

Is there any standard way for measuring the metric tensor. Does it require the a priori specification of a coordinate system relative to which we measure the components of the metric, or is there a way to measure the underlying geometric object?

I just discovered about solar storm named "Carrington Event"; I'd like to know how such a solar storm could affect my PC today. I found some publications: http://www.bu.edu/csp/EMMREM/papers/carrington.pdf...

Hi all I am looking to measure minute changes in electric field strength. I found this article http://www.physorg.com/news74876394.html" which describes how scientists at harvard isolated a single electron in a highly evacuated, absolute zero chilled chamber and manipulated its movement using...

Homework Statement I have a two spin 1/2 particles. The Hamiltonian for the system is given as H = w1 S1z + w2 S2z. I need to find the possible values and their probabilities when I measure S^2 at some later time T. Also the Initial state \Psi (0) = a | \uparrow \downarrow > + b | \downarrow...

I got fever, and due to the curiosity to know what is fever and on studying what is fever I got a doubt. why does temperature is high at anus when compared to other body parts at the time of fever.

The density of the material of a rectangular block is determined by measuring the mass and linear dimensions of the block. The table shows the results obtained, together with their uncertainties. mass = (25.0 ± 0.1)g length = (5.00 ± 0.01) cm breadth = (2.00 ± 0.01) cm height =...

Maybe this is a trivial question, I'm not sure, but when you measure linearly polarised light, such as that in the CMB which component of the light is 'measured'. By this I mean is it the oscillating electric field or the oscillating magnetic field that is oscillating in the direction of the...

As I understand it, the magnitude of an L_z eigenfunction's value is independent of its argument's \phi coordinate (the longitude). Or, to paraphrase Richard L. Liboff (section 9.3 of Introductory Quantum Mechanics), when a system is in an eigenstate of L_z, | Y _{l} ^{m} | is...

I am currently building an energy monitor according the the specifications of this site,http://openenergymonitor.org/emon/node/59. I understand how the current is measured but I am confused by the voltage measurement circuit. I do not understand how the step-down adapter can correctly...

Greetings, I have heard that one can not know one's absolute velocity, only one's velocity relative to other objects. But wouldn't the cosmic background radiation be blueshifted in the direction of motion and redshifted in the oposite direction? Thanks

dear all, some literature which I'm read, measuring blow by of engine can be execute use the pipe. not use with pressure gauge. how to measuring and calculating this if we must be use by pipe (not by pressure gauge)...? here is the ilustration...(attach) rgrds =wahyudi.jr=

HI I would like to test the thermal conductivity of r wall by K=Q*d/ A (t2-t1) K =conductivity d+=thickness A= area Q= heat flow my problem how I could simulate heat in my experiment and how I will measure the heat flow? could you please help me. Kind regards

I am undergoing a research term at my university working with photovoltaics. We are required to measure the concentration of Indium after doing copper etching processes with CIGS films. We've considered absorption spectroscopy but it will be weeks until we have the parts necessary to use this...

Hi all, I have been wondering how much energy does a candle produce per second. I know, that the heat energy can be measured, but what about the ionization energy? By ionization energy I mean the energy which is consumed when neutral atoms in the air are ionized. How can the amount of ions...

Is it possible to measure the supose end of the universe with a wave that will bounce of the end of the universe and return ?

Is there such a thing as lumens/m^3? Would you have to be measuring incoming light/energy from every (infinite) direction at the same time? Can it be estimated or got from lumens/m^2?

0. Bit o' background + greeting Hello everyone. I am a third-year math/physics/CS/AI major and I've never used this forum before, as can be seen from my impressive post count. I enjoy leafing through it though and find myself perpetually impressed by the activity and commitment of the community...

Suppose that we have a stochastic process and we suspect that the probability/probability density function changes with time, changes slowly in relation to the sampling rate. Two examples might be: 1. A QM experiment in which the source of identically prepared particles is not quite a...

A fathom is a method for measuring lengths, usually reserved for measuring the depth of water. A fathom is approximately 6 ft in length . Take the distance to the moon to be 250 000 miles, and use the approximation above to find the distance in fathoms . I try to solve : I fa =...

Most of the literature that I have read on non-relativistic wave mechanics discusses experiments that measure a particle’s position (double-slit, etc.). But I have found almost no examples of experiments for measuring a particle’s momentum. In general, I know that one measures the momentum of...

I need Help measuring central Vac low voltage circuit. I would like to put a relay in line if possible to trigger when the unit powers on. I measured 17.78 DC volts when off and then 0 when vacuum powers on. Seems like an odd voltage for the contacts that start the unit when you insert a hose.

I'm wondering how one would go about measuring the conductivity of a semiconductor with variation in temperature, I assume the non ohmic behaviour prevents one from making simple voltage current measurements and then inferring resistance and the conductivity...any answers much appreciated...

Hey I've been writting reports on strain gauge and thermistor. Ive completed my strain gauge report and now i am working on my thermistor report...ive been doing some research on them and i was wondering if this is the correct information i have gathered. so I have been asked from my...

I'm a building contractor looking for a way to measure the airflow (in CFM) of the vent fans that are typical in homes. The usual suspect is in the range of 80-150 CFM, has a squirrelcage fan installed in a metal housing that's installed in the ceiling, and a 3" or 4" round outlet that ducted to...

It is my understanding that a measurement of S_z followed by a measurement of S_y will result in a particle which is in an eigenstate of S_y . But it appears that a measurement of say S_y followed by a measurement of S_x results in zero. I see this from a question in which I am asked to...