Measuring Definition and 1000 Threads

The gas cloud known as the Crab Nebula can be seen with even a small telescope. It is the remnant of a supernova, a cataclysmic explosion of a star. The explosion was seen on the Earth on July 4, 1054 AD. The streamers in the figure glow with the characteristic red color of heated hydrogen gas...

I was wondering, how is it that scientists measure inertial mass. I presume they use F=ma, and thus the mass of an object would be measured by applying a force on an object and finding out the resulting acceleration. Getting acceleration is simple, but how can they measure the force? Then if...

A visitor to a lighthouse wishes to determine the height of the tower. The visitor ties a spool of thread to a small rock to make a simple pendulum, then hangs the pendulum down a spiral staircase in the center of the tower. The period of oscillation is 9.52 s. What is the height of the tower...

A student proposes to measure the gravitational constant G by suspending two spherical objects from the ceiling of a tall cathedral and measuring the deflection of the cables from the vertical. Draw a free-body diagram of one of the objects. If two 100.0 kg objects are suspended at the lower...

How can they be sure that the value for the AU is 149,597,870 km? What methods are used to measure it?

Reaction Time? how can you find reaction time from a velocity time graph? anyone knows i need an answer asap thanks a lot =).

hi. I am currently supposed to be doing a lab on the faraday effect, however the lab manual provided was poorly written and some what clumsy in the experimental procedure. I was wondering if any of you know a good site or book that explains a little about the theory and how experamental...

hi i've got to do measure hte refractive index of a liquid with mirror and lens first of all how can i measure hte refractive index of air in this way? i don't get how i can do this, please explain :| and then for the liquid, I've been told to put the liquid over the mirror and then the...

help with part b It has been claimed that an insect called the froghopper (Philaenus spumarius) is the best jumper in the animal kingdom. This insect can accelerate at 4400 m/s2 over a distance of 2.0 mm as it straightens its specially designed "jumping legs." I got this right (a)...

measuring distance using Ek and Ep??! okay, so the problem gives the following information a car(1 tonne) is traveling at 75km/hr, up a hill. Assuming gravity is 9.8ms-2 , how far will the car travel? so far I've done: Ek= (.5 x m x v^2) Ek= 36450000J 36450000=m x g x h 36450000=9800...

Hi all, I was rather hopeing that someone here may know of a way to accurately measure the frequency of a sound wave? The reason I need to be able to do this is to investigate the doppler effect. I am able to measure the start frequency accurately using the following piece of software...

i have always wondered how do the sensors meters carried in spacecraft s work in space, with all that harnessing radiation out there, how is that the cosmic rays, ultraviolet, x rays etc... don't fry it out

In lecture 9 of the second volume of the Feynman Lectures on physics, it is written... How can we measure [the field in the air above the ground] if the field is changed by putting something there? There are several ways. One way is to place an insulated conductor at some distance above the...

Measuring the relativistic mass and energy When we speak about a physical quantity we should define it and it is compulsory to propose a procedure of measuring it. But how does one measure relativistic mass? The answer lies in the fact that relativistic mass (as well as proper...

:confused: Hi everyone. I have this assignment whereby I need to use the parallax method to calculate the distance to a pole from a base line on our school field. I am kind of confused as to how I can apply the parallax method to do this on our assessment day. We know that on one end...

hello everyone, Im new to this forum but i really need some help doing a physics assignment. I am trying to use Newtons second law and the equation for wind resistance(click link) to determine the the angle made by a specific velocity. The link to the assignment is...

how do we measure the relativistic energy of a tardyon?

I'm trying to get my mind around this one. (stretching thin in the extreme) Black Holes Collide, and Gravity Quivers New York Times 05/02/2006 In the most precise effort yet to detect gravitational waves -- the quiverings of space-time predicted by Einstein's theory of general...

If I take an infinitely long, thin wing and measure its lift curve slope I should get 2pi. Now if I take a 1/2-wing and fit 1 end to a plate and test it in a wind tunnel, it should simulate the flow around a full span wing, am I wrong? Therefore measuring lift and working out the CL values...

ive done a test were, i get someone to try and distinguish to lines that are 0.25mm apart from varying distances. then I am going to do some kind of calculation to tell me somthing (hopefully) and i have done this experiement in different light levels, controlling the lux. and i have...

How can a photons velocity be slowed down when they pass through air, water, etc? If photons can be slowed down to slower than light speed, then would it not be possible for a "futuristic lightspeed rocket" to catch up to a photon? And also how can someone measure a slower speed (other than...

I have a simple question about a relativistic Doppler effect problem. To keep the math simple, I have intentionally left out the labels, you can view the speed of light as 300 miles per seconds, or 300 meters per second, it isn’t important. Speed of light = 300 per second Wavelength of...

A sample of silver with a mass of 63.3 g is heated to a temperature of 384.4 K and placed in a container of water at 290.0 K. The final temperature of the silver and water is 292.4 K. Assuming no heat loss, what mass of water was in the container? The specific heat of water is 4.184 J/(g C) and...

I wasn't sure where to put this thread... if it's in the wrong place, please move it. Anyways, I'm making a couple of posters for display and one of the showcases is featuing antique equipment like ohmmeters (Wheatstone bridge), ammeters, voltmeters, etc. I was wondering if anyone knew of any...

Hello I would like to find some texts or web sites explaining how and why activities can be measured with a Knudsen cell. What is measured and how the Gibbs energy is deuced from the measurements. I would also like to find out the range of application of this method, like for temperatures...

Hi all, I've been asked to search for a way, cost isn't that big of an issue, to measure flow rate in real-time of small, fast, abrasive particles (AlO2). These particles are, on average, 50 microns in diameter, and are shot out of a nozzle, itself just a bit bigger than 50 microns...

I understand that the range of extreme temperature is from 0-15million K. What are the ways that we can measure this? How did they figure out the temperature of the sun? thermocouple thermometer? blackbody radiation? optical pyrometer? I've tried searching for general information on these...

I'm curious about how very small forces are actually measured in the lab. I read somewhere that a dyne, for instance, exerts about the same force as a mosquito landing. What kind of set ups and instruments are needed to accurately measure a force that small, and smaller?

I need a bit of help here guys :D I have a something here that's effectively a battery that can supply around 1.5V I believe at a few micro-amps to a few milli-amps for an unknown amount of time. The problem is... they are all infact unknown quantities and I want to figure out what this...

ok, now I am lost... my base is the eigenvectors of L_z how do i measure the values of moment in some direction n=(a,b,c)?

if L_z|Y_l^m>=m|Y_l^m> whats my possible values for L_x(A|Y_0^0>+B|Y_1^0>+C|Y_2^0>)? i thought id use L_x=\frac{L_++L_-}{2}, create a matrix that would be block diagonal (a block for every l) and then i should find the eigenvalues for every block and say these are the values id get from...

Hi:smile: , How are u? I want to know how is multimeter can value capacitor. also what is design for it, I mean farad unit in multimeter. Thanks I appreciate it :cool:

Hello all. I would like to measure the tension on a very thin magnet wire and I have read about people making scales with a galvanometer (voltmeter). Basically, instead of using the meter to measure current, you send current thru the galvanometer and use the needle to exert force on an object...

Really confused with this entire section of my course involving chi squared and least square fitting. I have an assignment question in which 3 measurements of a poisson distributed quantity of counts over a fixed period of time, say N1, N2, N3.The variances associated with these measurements...

Hey, i got to do 2 experiements for physics to measure acceleraetion due to gravity, i did free fall experiment, dropping a ball from a certain hieght and measuring time n using the s=ut +.5 a t^2 forumula to get a and i need to graph this but i do not know what the two things i shot plot...

Hi, I've got this question where I have to describe two methods of measuring the pH of a substance. I've already got the one using electrochemical potentials, but I'm a bit stumped on the second method. What I've said is to carry out a titration with an alkali until the solution is...

Here is a question i can't figure out, it's a challange question we suppose to research.. Question: to measure acceleration, a bent arc-shaped sealed glass tube filled wtih water is used. there is a little air bubble inside. Explain the method of measurement in detail, and find the relationship...

Hey i was wondering i need to perform 2 experients (i can't do the penulum one) using completely different methods to measure the acceleration due to gravity. I thought of the droping different masses and using the ticky tape timer, ? Also where will i be able to find these things for...

Ok we just did a lab on measuring the inertial mass. This is going to be really hard for me to explain but i'll try. Anyways here's the problem the gravitation masses are given to us.The are 100g, 200g, 300g and 400g. We also have to use ticker tape and we ended up finding the acceleration by...

Hello all. I am trying to work through my problem sheets and I need some help from you guys.. I am trying to find out experimental methods to measure the size of the nuclei.. Thx so much K

Can you please help me with my problem? I need to measure how sound spreads trough foam. To measure it i need one source of sound and one recorder of sound. Ofcourse i need to change frequency and strength of sound to see if there is change in its spreading trough foam. I don't know how to...

I wanted to find the dielectric constant of different materials placed in a parallel plate capacitor using the equation: K = \frac{E_{dielectric}}{E_{original}} Where E = \frac{V}{d} I would use sensors connected to a computer to measure the voltage and i could easily measure the...

I'm suppossed to measure the height of a building tomorrow but I'm not exactly sure of how to do it accurately. Would using 'similar triangles' work? I would measure the length of the tower's shadow and my shadow. Using my height and shadow length, I could calculate the angle and use that...

As a result of his observations, Roemer concluded that eclipses of Io by Jupiter were delayed by 22 min during a 6 month period as the Earth moved from the point in its orbit where it is closest to Jupiter to the diametrically opposite point where is is farthest from Jupiter. Using 1.50 x 10^8...

The standard way to measure porosity of a rock is to get the pores completely saturated with water, then weigh the rock immersed in water and again in air (there are modified balances for this). Using Archimedes' principle, you then can determine the volume of the rock. Then you dry the rock...

hi can somebody just breiefly list me some points about ammeters and how they are inaccurate and why when measuring in current in nano and also about the cathode ray oscilloscope how when we plot voltages it is inaccurate and why. thanks just basically want to know the limitations of...

in measuring unknown emf by potentiometer, why must the stable current source(working battery) have a voltage greater than any voltage to be measured? i can't understand why.. in our exercise in physics, we used a slide-wire potentiometer with the assumption that 1 meter of the slide-wire...

This is a problem that has been giving me trouble, wondering if I could get some input: A space probe of mass m is dropped into a previously unexplored spherical cloud of gas and dust, and accelerates toward the center of the cloud under the influence of the cloud’s gravity. Measurements...

I want to know the formula to find the temperature of outer space by measuring the wavelenghts of the electromagnetic radiation coming from that area. Does anyone know what I'm talking about?

hi I need an experiment to measure magnetic filed in a solenoid. could anyone help me?