Measuring Definition and 1000 Threads

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

Hello everyone, I'm currently working on a little project that has been puzzling me for some time. If you send a laser beam into a fiber, the ingoing angle is sometimes slightly different than the outgoing angle. To measure this ratio of angles, I am currently using a setup that looks like...

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...

Homework Statement Describe how a venturi device for measuring the flow of water in a pope works and estimate the slowest flow rate such a device could be expected to measure using 20% of cross sectional area constriction and a mercury manometer. Homework Equations A1V1=A2V2 I also know...

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...

The question I have came from a talk I saw about the MINOS experiment. They say they can measure theta13 from their beam of mostly muon neutrinos by measuring electron neutrino appearance. Why would this not involve theta12? Is what is happening that the dominant chain is muon neutrinos...

Homework Statement A hiker is at the base of a mountain and can get the horizantal distance between himself and the peak through GPS device:750 m. And suppose we know the actual measurements: It's a right triangle with an opposite= 750 tan (pi/6) = 433 m , an adjacent= 750 m, and a...

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...

Homework Statement A small flat circular disc of diameter 2mm and mass 5mg is lowered vertically to rest at the centre of a flat tray of width 10mm in the x direction and 50mm in the y direction. What is the minimum uncertainty in measuring the velocity of the particle in the x direction...

I'm conducting a lab in which I change the distance of a lamp from a solar panel and use a multimeter to measure the resulting voltage. What type of relationship am I supposed to find? My results seem to indicate either a relationship with either a quadratic equation as its model or an inverse...

Light is conceived as a self-propagating perturbation of the EM field. This may sound like a silly question, but has this perturbation actually been measured/observed? Or is it accepted as the most parsimonious option that matches the evidence we have? My guess is that it is impossible to...

Homework Statement An astronaut arrives at a new planet, and gets out his simple device to determine the gravitational acceleration there. Prior to this arrival, he noted that the radius of the planet was 7040 km. If his 0.400-m-long pendulum has a period of 1.0 s, what is the mass of the...

Homework Statement A double-slit interference pattern is observed on a screen 1.0m behind two slits placed on 0.3mm apart. Ten bright fringes span a distance of 1.65cm. What is the wavelength of the light? Homework Equations Since we're looking at bright fringes: (m+1/2)\lambda =...

HI, How do i feed the current information into micro-controllers ADC input to calculate the total power? Please help. I am using atmel tiny45 and its a boost converter output current i want to measure for output power. Thanks.

Hi! I am looking for a way to measure the voltage on a Kelvin Water Dropper that I've built. This is quite problematic since the charge is small and the voltage is high. The only way to do it, as it seems to me, is to measure by influence. Any suggestions?

Pendulum measuring the restorative force HELP! Homework Statement A pendulum with length L is suspended at an angle theta. At the bottom of the pendulum, a string is attached to force meter. The string attached to the force meter is perpendicular to the pendulum string. In terms of F and...

Hi I'm a little confused when it comes to measuring the momentum in a infinite or finite square well. Is this even possible? One of the postulates of quantum mechanics states that measuring an observable will leave it as an eigenstate of that observables corresponding operator just after...

If you had an extremely sensitive scale (use your imagination) and shone a beam of light upon it, could you measure the force that the photons were exerting on the scale? would there even be a force?

Homework Statement It has recently become possible to "weigh" DNA molecules by measuring the influence of their mass on a nano-oscillator. Figure shows a thin rectangular cantilever etched out of silicon (density 2300 {\rm kg/m^3}) with a small gold dot at the end. If pulled down and...

Can anyone help me with a general working principle for the measurement of tension in a cable?

Hi everyone, I'm currently working on a project, a part of which involves building a sagnac interferometer. My group understands the theory behind its operation, and we are now in the process of collecting materials needed to build it. We are, however, unsure of a way to quantitatively...

I have to construct an experiment which measures the electric field strength at various distances from a charged Van Der Graaff generator. How would i go about this?

m=F/a then is mass measured in kg or g. Thanks

In Industry, what kind of plants would need to measure metal ions in their process streams. Ions that interest me are copper, nickle, iron etc. I've been trying to find some information, but only found some limited information on nickle but it did not include the information that I want, what...

Homework Statement a) Two observers are separated by a baseline equal to Earth's diameter. If the differences in their measurements of Mars' position at opposition (i think this means when it is closest to earth) is 33.6" (arcsec). What is the distance between Earth and Mars at opposition...

Hi people, i got a question regarding current measurement. Is there a way to measure it, other than by putting the ammeter in series? How do they find the current output from one IC to another IC and there isn't any resistance or cap between them? Thank you.

So I am Googling around trying to figure out how one would go about taking this measurement. I have learned the 'book way' of calculating the power generated by the engine/transmission system of a vehicle; but how does one go about physically measuring it? I am learning about different kinds...

Homework Statement I have a spectroscope that looks like this: Mercury/Helium lamp --> Split --> Lens --> Diffraction grating --> Lens --> Ocular I want to measure the grating spacing d with this setup. Homework Equations d \sin{\theta} = m \lambda The Attempt at a Solution Can...

Hi, I have a question about a fact that I did't understand, and all the world takes this as it is: How can the space-time distortion, generated by gravitational waves, can be measured? All scientist say that the space is stretched and squeezed, but how much means that, because 1 meter stretched...

Let me know if there are any errors or holes in my logic, facts, or assumptions. I was thinking in regards to time being relative to the observer and the resulting impossibility of an objective measure of time: In determining the age of the universe, our current estimation is about 13.2...

Temperature is basically the movement/ vibrations of particles. They vibrate only because they are in interaction with other particles/ fields - otherwise they would just fly in a straight line. As they have kinetic energy. Temperature = internal kinetic energy. How can one measure particles...

Measuring water level in tank...?? How to measure water level in tank in the cheapest way? The first thing that came to my mind is pressure sensor... but it's ruled out because it's expensive. Can somebody suggest a cheaper mechanism? And it is preferred to have a low power mechanism...