Scale Definition and 743 Threads

One of the intriging things to me about Causal Dymanical Triangulations is the implication of a fractal spacetime structure at small scales. Hunting around for related theories I came across Laurent Nottale's Scale Relativity theory. References to the theory after the late 90s are hard to...

Homework Statement Determine the vector that must be added to the sum of A + B in the given attachment to give a resultant displacement of (a) O and (b) 4.0 km [W]. In case anyone can't view the attachment, |A| is 5.1 km in length, 38 degrees N of E, and |B| is 6.8 km in length, 19 degrees E...

What happens to the Planck length due to the expansion? Does it grow with the scale factor?

If you stand on a bathroom scale, spring inside compresses .6mm, and tells your weight is 710 N. Now if you jump on the scale from a height of 1m, what does the read at it's peak? This is what I tried to do: I used Hooke's law: F_{}s= k*x and solved for the k which is spring constant...

Homework Statement You are standing on scales which read weight in Newtons. A 0.50 kg ball is dropped from a height of 1 m into your hands. Your hands drop from chest level to waist level during the catch, a distance of about 25 cm. Your mass is 62 kg. Assuming that you decelerate the ball...

Homework Statement You are standing on scales which read weight in Newtons. A 0.50 kg ball is dropped from a height of 1 m into your hands. Your hands drop from chest level to waist level during the catch, a distance of about 25 cm. Your mass is 62 kg. Assuming that you decelerate the ball...

Hey! I am having real issues finding a good scale for a graph I am drawing. Most of the data is around 0.001 to 0.005 but then there are a few that are all way up at 0.123. I am really having trouble finding a scale for all of this. I can find a scale, but not without having to squash half of...

Does anyone know, when an electron in an atom is exited by absorbing a photon, how long does it take for the electron to absorb the entire energy of the photon? Does the time scale depend on the energy level? Thanks!

Homework Statement A uniform flexible rope is suspended above a scale, with the bottom of the rope just touching the scale (gravity points downward). The rope has a length L and a total mass of M. The mass is uniformly distributed along it's length. The rope is released. After a length x<L...

If it was possible to build: A vertically mounted fly wheel - over 2 miles in diameter, the largest moving mass ever created by man. (half above ground, half below ground) Would it work? Would it continue to spin any longer because of its mass? Could it then be used to generate...

Hi, I am in my second astronomy course and just received a twenty question take home final exam, and I am having trouble with two of the questions. In 2004 astronomers reported finding evidence that certain white dwarfs are 12.1 +- 0.9 billion years old. Assuming an inflationary model in...

Hello I have a Gaussian Pulse in the frequency domain and transform it with the IFFT into the time-domain. My Problem is now that I can't figure out a way to give the sample points the correct time-scale. What kind of formula do I need to use? Thank You for helping me!

Referring to Nottale's Theory of Scale Relativity (http://luth.obspm.fr/~luthier/nottale/arIJMP2.pdf), I've been reading an awful lot about this theory and it seems to present, in my opinion, the best candidate for a unifaction of quantum mechanics and general relativity. The postulates of...

[SOLVED] Lift, reading on the scale Homework Statement Mandy stands on a weighing scale inside a lift (elevator) that accelerates vertically upwards. The forces on Mandy are her weight W and the reaction force from the scale R. The reading of the scale is A. R + W. B. W. C. R. D. R – W. The...

I am working on a project to make a large scale electromagnet and try as I might I just can't get past one part. Getting it to magnetize. I have built the unit primarily out of a 5 ft rod of threaded steel (I will be replacing it with iron I just happened to have the rod already) wrapped in...

You hold in the palm of your hand a classical particle with momentum P = (E,cp_{x},cp_{y}, cp_{up}) where cp_{up}=0 . Placing it gently on a scale you ask, what part of P = (E,cp_{x},cp_{y}, cp_{up}) is pushing down on the scale?

I brought an old analytical balance into my kid's elementary school for "Science Day", and I explained the difference in using a scale (measures weight) and the balance (measures mass). I told them that although objects on a scale will weigh different amounts depending on if they are weighed...

Is there a good site somewhere on the net with a to scale animation/simulation of the solar system? I haven't seen anything yet. Thanks in advance.

My skill with proofs and number theory is very limited and my use tends toward the stereotyped physicist. Dealing with infinities and identifying exactly what assumptions are in play has become somewhat an issue for me though. My questions are contained in the following visual tool. Please slap...

EDIT: I corrected a typo below: I had forgotten to put my entire expression for a(t) to the power 1/3. It's corrected now This may sound like a silly question but it's bugging me quite a bit. Consider a cosmological model, let's say the simple case of no pressure, no cosmological...

Never mind! I realized the answer to my question. Consider solving Einstein's equations in a FLRW universe and assume that there is no other force acting on matter/energy beside gravity. Let's say I want to find the full time evolution of the scale factor a(t) (and knowing...

Extension of Einstein's principle of relativity: http://en.wikipedia.org/wiki/Scale_relativity How well known is this idea, and what's its status?

Homework Statement I must determine the mass of 2 objects with lab equipment and 50g mass pieces a scale may not be used as well as density. Homework Equations have no idea The Attempt at a Solution have no idea

When I step on a scale I see that it says...70kg. We typically call this value weight? However, kg is used for "mass" and not "weight". So when we say 70kg do we mean that my mass is 70kg OR do we mean that my weight is 70 N? So if it does mean mass, then my ACTUAL weight is 686N! lol And...

I am taking a Math/Cmpt class and I am useless with this program that we need to use Matlab. Q: The derivative of a function f(x) can be approximated at the point x=x(sub)0 by a forward divided difference f'(x(sub)0) ≈ [f(x(sub)0 + h) - f(x(sub)0)] / h or by a central divided...

a b ___ | | | | | | | | | | | | | | _____________________ | | | | |___| |_____________________| ============= =============...

Homework Statement See image Homework Equations M = log(I_i / I_o) The Attempt at a Solution See image

To date, the little higgs implied by some SUSY models requires higgs of energies less than 130 GEV, which Fermilab's Tevatron has not yet seen. These models do help explain EW breaking, however, If SUSY explains E-w scale breaking, does it require a little Higgs at Tevatron energies? I...

1. A 11.4kg block of metal is suspended from a scale and immersed in water. The timensions of the block are 12.7cm x 9.9cm x 9.2cm. The 12.7cm dimension is vertical, and the top of the block is 4.94cm below the surface of the water. The acceleration due to gravity is 9.8m/s^2. What is...

Spectrometer vernier scale. Quick answer please! This is a quick question. I am measuring the emission spectra for hydrogen, but now I'm finding myself wondering about measurements in the vernier scale. I have the right and left angle measurements; however they differ by more than 180 degrees...

Homework Statement suppose that a spring is used in a spring scale that is limited to a maximum value of 25N, but you would like to weigh an object of mass M that weighs more than 25N. What commonly available equipment, along with the spring scale, can be used to determine the weight of the...

Homework Statement * A 14.0kg block of metal measuring 12cm x 10cm x 10cm is suspended from a scale and immersed in water. The 12.0 cm dimension is vertical and the top of the block is 5.05 cm below the surface of the water. (a) What are the forces acting on the top and on the bottom of...

Does anyone know the significance of 1233 degrees Kelvin?

I would want to create medals is it possible to do this on a small scale

An elevator is at rest with a bag hanging from a spring scale. My question is Which force gives the scale reading? The mg (the weight of the bag) downward or the force exerted by the scale on the bag Fn gives the scale reading? thanks.

Hi! I'm struggling with this question: A neutrino of energy 10 GeV collides with a proton at rest producing a 9 GeV muon deflected at an angle of 0.01 radians away from the initial neutrino direction. The collision is used to probe the momentum distribution of down quarks in the proton. Show...

double log scale - please help I am trying to find/create the equation for a straight line on a double logarithmic scale graph - what is the format of the equation or how do I do this using data points from the graph.

Help please! Here is the prob and i don't not know where or how to begin. 1.Jose was having a really bad day out on the bike. He should have checked the forecast. First, the wind coming out of nowhere. Must have been a steady 30 mph with gusts up to 50, head on. Then the lightning. First 1...

Hey guys If the output of the function generator for a sinusoidal waveform is 6 voltage divisons peak to peak along the voltage axis- and the voltmeter reads 2.12v, find the volts/div scale that is being used? for this do just divide the volt given by the division given?, please help,(pretty...

#1 On takeoff, the combined action of the engines and wings of an airplane exerts an 8000N force on the plane, directed upward at an angle of 65* above the horizontal. The plane rises with constant velocity in the vertical direction while continuing to accelerate in the horizontal direction...

Hi all, as a school project we are trying to build a small scale windtunnel. I've been doing a lot of reading, the design of the tunnel is basicly done now. But now comes the real math's. So I got a few questions which i hope that can be answered by one of you guys. To deside the scale of...

A 62-kg girl weighs herself by standing on a scale in an elevator. What does the scale read when the elevator is ascending at 11 m/s but its speed is decreasing by 5 m/s in each second? I'm not really sure where to begin.

This idea is for an alternative to large scale energy storage. Sorry for the double and confusing post (https://www.physicsforums.com/showthread.php?t=179768), I should have posted here in the first place. As far as I can understand, pumped-storage hydroelectricity is the main technology used...

Hi everyone, I had to write about the cardiovascular system in biology and that got me thinking, would quantum effects alter the flow of oxygen or other chemicals around the body? Atoms really aren't that small, electron microscopes can after all see them, but at what scale do quantum effects...

A couple years ago it was typical to see in articles, and to hear in conferences, specially when discussing about the hierarchy or about meeting of the coupling constants at GUT scale, of some other examples of misleading coincidences. The most prolific example was the coincidence between the...

What would an 80/100 translate to on the 0-4.0 scale at most universities?

The empirical MOND explanation of galactic rotation curves involves switching over in the low acceleration regime from the Newtonian acceleration Gm/r^2 to the MOND acceleration term sqrt(Gm a_0)/r. This is normally achieved using an "interpolation function" which effectively switches off one...

I bought a 80g x 0.01g scale from ebay and it came with a 50g weight. Now this weight is exactly 50g up to more than 1mg, I suppose? But when I put in on, it read 50.08g. So the scale is off it seems. There are instructions to recalibrate the scale but it seems like the instructions are talking...

Hi to all, I have a quantum question to post here. In the discussion on atomic theory, we know that electrons in different orbital levels have different quantum energy, say n=1 and n=2 have different energy levels. When one electron 'jumps' to another energy level, say from n=2 to n=1, the...

Hey, How do u arrive at the state diagram for a scale of 10 gray code counter? I know how to draw all the used states, but the problem comes when the unused states are considered. The unused states namely are:1100 0100...