Measuring Definition and 962 Threads

Homework Statement You are a judge in a children's kite-flying contest, and two children will win prizes for the kites that pull most strongly and least strongly on their strings. To measure string tensions, you borrow a weight hanger, some slotted weights, and a protractor from your physics...

Homework Statement At your disposal are a scale and a measuring tape. You are not allowed to jump on the scale. How would you go about measuring the average power you exert on the floor?Homework Equations P_{average}=\frac{\Delta E_{tot}}{\Delta t}The Attempt at a Solution I am honestly lost...

Hey, I'm trying to build a stroboscope for measuring the RPM of a few different fans. So far I've tried using LEDs but haven't been very successful. I tried using a function generator with square pulses (I tried both 20% duty cycle and 50%). So I started at 1 Hz and kept on increasing the...

I have to measure gravitational acceleration, and calculate my rate of error. The experiment i came up with is: a thick plastic tube, with no air inside, on the top side some sort of release mechanism, then have two motion detctors, 1M apart from each other, hooked up to a stopwatch to measure...

Please ignore the periods in the diagram as it won't allow me to properly draw it otherwise. I have an object, attached to a string, rotating uniformly in a circle but at an angle to the horizontal plane. It is going at 80RPM (so relatively slow). How would one go about measuring the length...

Hi. I'm trying to measure the milliseconds of duration of output from a little piezo speaker that is on a circuit (a freezer control unit). I tried connecting an oscilloscope across its leads, but when I apply power, I hear this resonating noise which does not sound healthy. This is only when...

A one liter cylinder is filled with 0.1 mm steel beads and the void volume is measured. A one liter cylinder is filled with 1 mm steel beads and the void volume is measured. A one liter cylinder is filled with 10 mm steel beads and the void volume is measured. Which bead size has the greatest...

Hi Everyone, First post here. I'm a 37 year old man who has just recently begun dabbling in the basics of Physics, purely for the academic enjoyment of making by brain go "ow!". Upon reading the "bowling ball on a bed sheet" description of how the gravity of large objects can bend the...

Hi, We have an assignment in my physics class and I am not sure where to start. We are suppose to duplicate Galileo's experiment, using the concept of similar triangles to calculate the height of the object. 1. What is the height of the three objects on the moon in miles? 2. What are the names...

So we had a thread about the FQXi essay contest a couple weeks back, and when I first saw the winners list this one... ...jumped out at me, both because the inclusion of the word "undecidability" indicated the paper might actually touch on matters (i.e. formal logic) I feel qualified to...

Has the permeability and permittivity of vacuum ever been measured in a vacuum or space?

What the title implies, with the discovery that the universe is expanding, are we observing the systems becoming harder to see? You'd think that with the speed of the objects and the distances involved, things like brightness and actual size would be getting reduced...

Suppose I'm alive and well and living in the 17th century and I want to make observations of times when Jupiter's moon Io disappears behind Jupiter. The best way to do this is to use the regular motion of the stars in the sky as a clock? What kind of accuracy could the best equipment of my day...

Hello, How can I measure how much torque I'm exerting on a lever? Can it be done with a torque wrench? Or do I need ? Thanks

We can measure the expansion of space via the galactic redshifting. Please for now excuse my order of mag. estimate, but in mks units, Hubble's constant is roughly: H=2\times 10^{-18} {\rm m/s/m} If this exapansion was much larger. Say H'=2\times 10^{-10} {\rm m/s/m} Could a...

The other day I was reading a simple experiment to determine (yes, very roughly) the constant of gravitation, all using simple tools in your basement. http://www.fourmilab.ch/gravitation/foobar/" What struck me about this experiment is another that I remember from childhood cartoon...

Hi there, first off I hope this is ok to post here. Quite a simple question. I have done an experiment simply to work out the resistance of a thermistor at different temperatures, I did a prelim with a simple circuit of just ohm meter + thermistor. Then I did the main one with a potential...

What could you do to obtain a more precise measure of the elastic modulus of a material in tensile testing?

for a physics project i am designing a vertical wind tunnel made out of stovepipe and powered by a leaf blower. this experiment is designed to find the terminal velocity of different shapes. We already have a way to vary the wind speed, but what we don't have is an accurate way to measure this...

What is the coefficient of friction for a metal mass sliding down a wooden slope? Mass=0.50kg Slope distance=1.83m Angle=54 Degrees Time=1.06 s Vi=0m/s g=9.81m/s/s For this question we had to write out a formula and find mu. I first found acceleration to be 3.257m/s/s, Friction force to be...

how do i measure the current flow threw the neutral wire if phase R is open circuited? the impedance per load is 3+7j

Consider please that an observer is located in a plane sinusoidal and polarized e.m. wave. He erects a metalic antenna normal to the direction of propagation. A sinusoidal potential difference appears between the two ends of the antenna having the same frequency as the e.m. has. Is that a...

i've got an engine to work with, and i have the basic specs of it like peak hp @ an rpm. but, i don't have figures for torque. I need to know how i can measure the torque of the engine with different fuels. I calculated the torque of the engine from their hp figure, but I'm having trouble...

Homework Statement I need to draw a table measuring bendiness but I don't know what unit or how bendiness would be measured. Homework Equations // The Attempt at a Solution I have drawn the table up, just I need a unit for bendyness

In case of 3d free particle Schrodinger equation solution, the angular momentum eigenvalue L-square =l(l+1) and a free particle has a wavefunction as the superposition of all 'l'(angular momentum) states.Now the difficulty is that when I will measure the L-square, is it true that I will endup...

I heard that it is possible to measure positions of individual atoms in a crystal. Is this true? I understand the principle of measuring crystal orientation and base vectors of Bravais lattice with X-ray, but I have no idea how positions of individual atoms can be obtained. I suppose it is...

Homework Statement how do we measure 2 forces on an angle? let's say we get an object that is moving ( a rocket?) the gravity pull it down while the rocket engineer gives more force. however to reach the highest height, we shot it at 90 degree(horizon). and also at that time, the...

I am newbie in this forum as well as in this field. Recently, I learned human body has certain frequency. I want to experiment measuring the frequency, volt, current upon the human body. any recommended equipment and the best way to measure all three? 1. frequency 2. volt 3. currency...

Hi, even though this is my first post, Physics Forums have helped my a over that past couple of years. Just searching old PF threads usually gave me the answer I was looking for. So thanks. I am currently doing Advanced Higher (Scottish Qualification) Physics Investigation on Viscosity. During...

What would be a relatively simple methodology to measure the CO2 concentrations of the air? Any help is appreciated. Thanks!

If we measure a particle's momentum don't we need to use some measure of the particle's position to find out the momentum ? How is momentum calculated if not through a measure somehow of the particle's position and how does this relate to the uncertainty principle?

Assuming a system A with v=.8c wrt system B At x=0 in A we have 4 EPR "transmitters" wih receivers at x=10 , x=(-10) in A and x'=10, x'=(-10) in B At x=0=x' at time t=0=t' an instantaeous epr polarization event is transmitted simultaneously by the four transmitters. Can anyone suggest...

effect on Flow and pressure measuring due to turbulent flow of air Hi, I want to measure the air flow rate using a device which will basically measure the velocity of air and converts that in terms of flow rate reading. For creating flow of air i have used vacuum pumps which is connected by...

I have heard numbers like our Universe is 75% Dark energy, 25% Dark matter, and 5% baryonic matter or something. For my question, the numbers are irrevelant. My question is just what exactly is being measured? Brandon

In CM, we have a prescription for measuring momentum. Velocity is defined, and we can measure it, and we can find out the momentum. Now, does quantum mechanics have the same prescription for measuring momentum (for a single free particle at least) ? I mean, for a single free particle, can we...

Hello all, Im new to the site so please don't hurt me :blushing: ! My final goal is to measure linear speed of a pedal powered car, and send the speed wirelessly to my laptop which will record the speed profile. My problem is that I can't find a sensor that will measure angular...

I am currently working a project to evaluate the power output of a single pulse through an air core transformer. Using a scope to measure the secondary output and I am confused on what voltage to use. Scope shows DC voltage, peak voltage, drop Voltage differntial of peak and drop voltage. Would...

Is it possible to test the CO2 pressure in a soda bottle as simple science project that can be done at home? What kind of apparatus is need? The original goal is to test if CO2 pressure changes at different temperatures. It would be helpful if anybody had any suggestions on how to go about...

How do we measure cross-sectional area of a cable (obviously circular)? For example, diameter of a cable as measured from vernier caliper was 19.5 mm. If we apply A = pi(3.14) r2, answer is 298.49 mm square but tag on said cable is showing Area = 10mm square? Please explain.

How to Measure magnification How can I see how strong a magnifying glass is? I hear a lot of people talk about magnifying and how strong the magnification is, but I would like to know the true magnification of my magnifying glass. I have a few of them and some seem stronger then...

Premature, I am well aware. However, I was given an assignment to write an experimental procedure for measuring the spin of the Higgs Boson. I've already finished the paper so this isn't homework, but I am curious as to the motivations of my Professor. It is my understanding that the Higgs...

How to Measure magnification How can I see how strong a magnifying glass is? I hear a lot of people talk about magnifying and how strong the magnification is, but I would like to know the true magnification of my magnifying glass. I have a few of them and some seem stronger then...

I think I am missing something in Schrodinger's Cat... Wouldn't the Geiger Counter cause the wave function of the decay to collapse because the Geiger Counter is interfering with the wave function? Would the Geiger Counter end the superposition of the particle? Does the problem lie with what the...

Show that if E is a Borel measurable subset of R, then {(x,y)| x-y is in E} is also measurable in the product space of Borel measures... Also, if f is a measurable function, show that F(x,y)=f(x-y) is also measurable..

Homework Statement An inclined tube reservoir manometer is constructed as shown in the figure. Analyze the manometer to obtain a general expression for the liquid deflection L in the inclined tube in terms of the applied pressure difference \Delta p. Also obtain a general expression for the...

Can anybody provide an example of a device capable of "directly" measuring position relative to some origin on a microscopic scale? By microscopic I mean on the scale that QM is important.

Hello, I got a pratical problem; I want to know the gas temperature of SF6 gas inside a vessel. I can't insert a temperature probe to measure the temp. What i can do is clamp a temp. probe to the ouside of the vessel. Does this gives me a realistic reading, bare in mind the wetter...

Hi, I've decided to make my own meter for measuring laser power to around 10% accuracy if possible. Optical power meters are way too expensive for me though. One building block I've decided to use is a phototransistor, because I've found one which has very good linear response - when measuring...

Hiya, Question 1: (Main question) I bought a lux meter while understanding very little about how light is measured. I'm hoping to measure the output of a laser in mW. I assume it's possible to do this at least to an accuracy of about 10-20% which is all I need? If so, please could someone help...

How would an imaginary microscopic being measure distance or more precisely measure its position in some spatial coordinate system?