Scale Definition and 743 Threads

I will be writing my final exam tomorrow evening, and I am currently terribly stuck on the following practice problems. I have posted my thoughts below each problem. They look tricky to me. It would be very nice if someone could help me out and I will remain eternally grateful for your help...

Homework Statement I just used the Kundt's tube to illustrate the effect of a standing sound wave in a glas tube. The characteristic nodes and antinodes were perfectly visible and some small scale striated vibration patterns at the antinodes were prominent. What is the physical explanation for...

We are given a form of Einstein's field equations: 3R'' = -pR R''R + 2((R')^2) = p(R^2) where p is a constant and R' = dR/dt Assuimg that R and R' are both positive, we are asked to show that the general solution is R(t) = A*[(t-ti)^(2/3)] I'm very confused about this. If we...

What is the ratio of the scale factor now to the scale factor at the end of the inflationary era? Edit: In other words, what is the z value of the end of the inflationary era?

If you look at the planets, they group into a star, which all form a galaxy. It just seems like everything groups together. Our observable universe with the Hubble isn't as enormous as the universe may be. If so, galaxys would form an even greater cluster and so on and so forth.

What happens with causality at the Planck scale? Can effects "precede" causes? I would like to know what happens with causality at the Planck scale, explained in "educated layman" terms, if that's possible... :) Might effects "precede" causes in time? Do we have to redefine causality at the...

Homework Statement Assume that the current age of the universe is 13.4 billion years old, and that we live in a matter-dominated, omega_m = 1, critical universe, what is the age of the universe at redshift 0.6? HINT: use the current age of the universe to pin down the proportionality...

Hello, here's my problem : I was introduced the Gauss algorithm used to scale a matrix (to obtain a triangular matrix in order to solve a system of equations), but my teacher says that we can only use the pivot line to null the rest of the numbers of the column. The fact is I have done quite...

A pulley Problem Homework Statement So, in the diagram attached one mass is 1 kg, and the other one is 2 kg. and what would be reading on the scale Homework Equations F=ma The Attempt at a Solution I think this is very much like an elevator problem where the elevator is moving...

A Wikipedia article says: "The surface of the inner core exhibits rapid variations in properties at scales at least as small as 1 km. This is puzzling, since lateral temperature variations along the inner core boundary are known to be extremely small (this conclusion is confidently constrained...

arvind drops a scale vertically which is grabbed by Vijay whose hand is just below the scale. In the mean time the scale slips by 20cm. What is the reflex time of Vijay?

Hi,I had this problem which I cannot answer. I would appreciate if someone could help me out. Here's the problem - Homework Statement In the labaratory,you are asked to determine the mass of a meterstick without using a scale of any kind. In addition to the meterstick you may use ...

The Kardashev Scale is a scale (duh) that judges civilizations based on their energy output. There are Three Types: Type I: 1.74×1017 W Type II: 3.86×1026 W Type III: 10^36 W Now, its is said that civilizations will grow like this: Type I: Uses the energy output of One Planet...

I'm stuck, again, on a particular passage of a book (jean zinn justinf's QFT and critical phenomena). it says: We will find it convinient to t -> t/hbar , the action is then written as: S_{0} / \hbar=\int_{t'}^{t''} dt [\frac{m \dot {x}^2(t) }{2 \hbar^2} + V(t)] where t' and t'' are...

I'm supposed to determine if a bunch of materials have a high or low impact strength. I did the hard part and determined that the impact strength for each material, but I don't know a relative scale. What is a high value on the izod impact scale test(it's measured in joules). Any idea?

Hey! I'm new here.. and I desperately need help for some PHYS12 hw.. I hope I'm in the right place. My new teacher has a strong russian accent so I don't understand a single word he ever saids. A uniform 1.3 kg beam hinged at one end supports a 0.5 kg block. the bean is held level by a...

A 1.5kg crate falls from a height of 2.0m onto an industrial spring scale with a spring constant of 1.5 X 10^5 N/m. At its greatest compression the reading on the scale is: My work: mgh= PE (1.5kg*9.81m/s*2.0m)= 30J The potential energy of the crate is 30J The Force of the crate is...

hi all! I am not a physics but enginereing major. I am confusing about what's going on with heat tranport in micro- scales. I encounter terms like phonon-electron interaction, electron gas, lattice etc.. What exactly is a phonon? does it posses mass? What is electron gas? Could anyone...

I have a problem that shows a picture with an arrow in it. The arrow in the picture shows that is is 5 cm in length. The actual length of the arrow is given in the problem as 43 m. The question asks for me to determine the scale of the picture. So, I've set up a ratio: 1/x = 5/45 (1 cm...

Hi firstly Thanks for the help... I am not very good at forces ... and spring balances etc... Q1 A 10N force is pulling up on the ring of spring scale that weighs 2N. If an 8N mass is attached to the bottom hook of the scale, what is the scale reading? I figure that the mass of the...

In the macro, non-relativistic world, let's say that the present is the interval that separates the future from the past. And that this is an analogy for the interval within which the probability waves in a region in space collapse into particulate matter resulting in a measurable event which...

beaker with water on a weighing scale... A weighing scale has a beaker of water on one side and a balancing weight on the other side. You put your finger into the water carefully without touching the beaker. Will the balance be upset? Which side will appear heavier, if so? What will...

Hello, I had a question about the Cassimir effect. As I understand it the force is created by an Electromagnetic radiation vacuum created in between two closely spaced metal plates and since only non-half integer wavelengths can exist in this spacing, the plates are drawn slightly closer...

In a screw gauge, the pitch is defined as the distance traveled in one rotation. Is it also equal to the length of one main scale division? If the length of one main scale division is not given, then can we take it to be equal to the pitch? Or do we take it as equal to some other default value.

How do I change the scale of the x-axis so that it does not automatically plot the number of data I graph but my customised x points? My situation: I like to graph hundreds of different points or data But only want the x-axis to be from 0 to 3, including decimals in between.

Im doing a project and i did some test with AL using the Rockwell/Vickers machine and I was wondering if the units i have are in Kg and if they are I need to pick a unit to change them to so i can have a scale what should I use. my teacher was saying something about using the K value for the...

I basically am having a problem understanding the units used on the atomic level such as MeV/c and MeV/c^2. I have a problem where I have a given energy of 370 MeV for a photon. This means the wavelength is \lambda = \frac{{(6.6261*10^{ - 34} )c}}{{(3.7*10^8 eV*\frac{{1.6022*10^{ - 19}...

A 1-kg beaker containing 2 kg of oil(density = 916 kg/m^3) rests on a scale. A 2kg block of iron is suspended from a spring scale and completely submerged in the oil. Find the equilibruim readings of both scales. For the bottom scale, I can find the weight, 29.4 N of the beaker and oil, but...

I read somewhere something about observability, and things which are infinitely big, or infinitesimally small. Basically, the question is whether it would be possible to make an observation of an infinitely long yardstick. If it existed, could you observe it in it's entirety ? is it possible ...

I am working on a homework for a programming class. We have to create a Logarithmic plot and add to it a marker when the program is running on the click of the mouse. That is NOT the problem :) , in fact, that's very simple! My problem, however, is with the scale. When my plot is in linear...

Hi everyone i have comed across a fairly difficult question in chemisty that's been baffling me. A 51.1 mL of 0.153M NaOH was mixed with 27.5mL of 0.0147M H2SO4. What is the pH of the resulting solution. What I want to ask is shouldn't the resulting solution, water, be neutral with pH of 7...

http://www.lightningpacks.com/" to recharge your dig cam batteries on a wilderness hike. "Carrying weights of between 44 and 84 lbs, testers generated up to 7.4W,..."

I am asked to prepare some information on ph scale. I know what pH is, I know how to calculate it in some cases, I know it is lower than 7 for acid and higher then 7 for base - is there anything more important? G

you are standing on a scale in an elevator. the scale reads 176lb when the elevator is at rest. the elevator begins to accelerate upward at 12ft/s^2. what is the reading of the scale? i converted 176lb to 80kg. i know the sum of all forces equals mass*acceleration but i don't know what...

formula Help! i got this question but i don;t know which formula to use Q - A 1m plank of Mass 1.0kg is placed on two scales which are at either end of the plank. Masses are hung underneath the plank. Mass A = 5.0kg at a distance of 0.30m from the left of the plank Mass B = 5.0kg at a...

Hi, this problem gave me some trouble and I'm not sure if I did this correctly. The problem reads: A 75-kg person steps onto an elevator with a scale. What does the scale read when the elevator (a) is at rest, (b) climbing at 3.0m/s, (c) falling at 3.0m/s, (d) accelerating upward at 3.0m/s^2...

A person stands on a bathroom scale in a motionless elevator. When the elevator begins to move, the scale briefly reads only 0.67 of the person's regular weight. Calculate the acceleration of the elevator. how do i start this problem? help please!

http://www.arxiv.org/PS_cache/astro-ph/pdf/0508/0508047.pdf

Need a help on how to go about building a Laboratory scale using strain gages I need to build a scale with a working range of 2 to 200 gm, an accuracy of at least 2 gm, footprint of no more that 16 in sq, and use no more that 6 strain gages. I believe I need to set up the strain gages in...

During a physics prac today, we were using a traveling microscope with a vernier scale. My demonstrator told me I was reading the scale wrong, and as much as I tried to convince him otherwise he insisted he was right. Can anyone here tell me what the correct value to be read from the vernier...

If two 100-N weights were attached to a horizontal spring scale would the scale read 0, 100, or 200 N, or would it give some other reading?

Hi All, I would like to hear opinions about an explanation I gave some time ago to provide physical fundamentation to the concept of instantaneous velocity. I started showing a typical situation where one calculates average velocity between events separated in time by one second. Along the...

I need to find the mass of an aluminum rod without the use of a scale. I have all the dimensions of the rod but I just don't know the right equations etc. Thanks for the help!

Hi All, I was wondering if someone could help me with a basic understanding of the scale of things in our body. I love this little animation that Brian Greene has out there http://www.pbs.org/wgbh/nova/elegant/scale.html I know very little about biology, so you’ll need to humor me if...

What is "scale radius" I've tried posting this on the Cosmolgy and astronomy forum but got no reponses yet.* Of course it only been a few days but I'm impatient... *I've been researching dark matter lately.* Evidence for it in spiral galaxies is the fact that the stars revolve about the...

Hello, I'm writing a bit of an absurd business plan, and I'm faced with ethical considerations. I'd like your advice. The plan consists of using certain species of monkeys as laborers, on a massive scale. The monkeys will be bred, trained and employed to carry out specific tasks, which can't...

ok on a scale from one to ten exactly how likely is it for M-theorie to be true?

After a spectacularly unsuccessful first post--the silence of the replies was deafening--I would like to again beg the simplest of answers. I am aware that most forums of this kind do not allow unqualified pontificating, yet I'm seeing quite a few ‘ideas' being put forward, and they often...

Wow, just found this great little link that gives an awesome perspective on the scale of things. Just thought I would share: http://www.pbs.org/wgbh/nova/elegant/scale.html

My sister's having kind of a rough time in high school this year. I was talking to her about it and I was really surprised to find out what her school's grade scale is: Numeric Average | Letter Grade | Description 90-100 | A | Excellent Progress 80-90 | B | Good Progress 75-79...