Reference Definition and 1000 Threads

Homework Statement The steel ball is suspended from the accelerating frame by the two cords A and B. The angles (they are on the inside) are both 60 degrees. Determine the acceleration of the frame which will cause the tension in A to be twice that in B. The acceleration is going to the...

Hi I know that the following can never be done in the real world, but in theory, if the vectors of all particles, antiparticles, photons etc. in the universe could be summed, would that qualify as an absolute reference frame for that instant in time? Clearly each instant would have a...

Hi I'm in the middle of writing up the Frank-Hertz experiment as part of my lab module this year, but I'm having trouble finding a 'reliable' website that I can use to quote the electron energy value (ie 4.9eV). I'm afraid my lecturer refuses to acknowledge wikipedia as a good source...

For those of you who don't know, "Formulas and Theorems" is basically a compilation of thousands of math theorems, 6000+ formulas, with a summary of their proofs, covering most of what was known in the late 18th century. What I'm looking for is a comprehensive reference book with worked...

I've seen several responses (and links) to the question "What happens when something is traveling at the speed of light" and understand that the answer is twofold. First no object can travel that fast because it would require an infinite amount of energy to acelerate physical objects to that...

so here r ma doubts => it is sometimes heard tat inertial frame of referance is only an ideal concept and no such inertial frame exists.comment. =>the accelaration of a particle is zero as measured from an inertial frame of referance . can we conclude tat no force acts on it? => a...

Does anyone know or have a reference indicating what PLC [programmable logic controller] brands are popular in China?

Suppose event A causes event B. To one observer, event A comes before event B. Is it possible that in another frame of reference event B could come before event A? If so, how?

Since in our proper frame of reference the fall of material into a black hole would appear to take for an eternity, would it not follow then that all black holes would appear as these instead? Would in fact all black holes appear this way? What if you have a small black hole and then have...

I'm having trouble writing out a reference for a book. My normal format is: Author (year of publication) Title publisher, place of publication eg: Trueman, A.E. (1949) Geology and scenery in England and Wales. Penguin Books, Harmondsworth This book is a revised edition, revised without help...

Our planet is moving through our solar system and our solar system is moving through our galaxy and our galaxy is moving within the local group and are local group is moving through our universe, so how fast are we moving right now, and if i then jump into my spaceship and accelerate am i...

Simple question. Are reference angles always positive??

[FONT="Arial"]Hi, Is there any book that can be read as an alternative to the 'Cambridge Encyclopedia of the Sun'? I have not been able to buy the above but wanted to know if there are any other books that might have the same information. Thanks Nitya

dealing with non-inertial rotating reference frames, real forces such as the centripetal force need to be taken into account,or only the forces that can be really observed within the frame? because from the perspective of the rotating frame, objects should be at rest. it only appears logical...

My textbook basically defines an inertial reference frame as follows: If you have an object O that has no forces acting on it, and there is a reference frame R where the acceleration of O with respect to R is zero, then R is a inertial reference frame. This to me seems circular. How does one...

:rolleyes: First, I will state the problem - A hauling truck is traveling on a level road. The driver suddenly applies the brakes, causing the truck to decelerate by an amount (g/2). This causes a box in the rear of the truck to slide forward. If the coefficent of sliding friction...

Does anyone know why I can find a printable sheet with all the common derivatives? I know most off the top of my head, but I need to review a few like logs and inverse trigonometric functions. I need something to use as a good study sheet. Thanks.

At t=0, a flywheel has an angular velocity of 4.7 rad/s, a constant angular acceleration of -0.25 rad/s^2, and a reference line at θ(t=0)=0 rad. Assuming the motion proceeded similary at times before t=0, at what negative time was the reference line at θ=-10.5 rad? Based on this question I'm...

Hi - I've just started having lectures on special relativity at uni. We were talking about inertial reference frames and how these can be characterised by the facts that: 1) They move relative to one another with constant velocity, and 2) Newton's laws operate in inertial reference frames...

c) What is the relative velocity of the two reference frames?

if i drop an apple while riding on a bus that is moving along a level road, and a pedestrian outside sees me do it... won't the pedestrian see motion at a curved motion downward with an initial vertical velosity?

:confused: I am in desperate need of help with a certian physice question I am struggling on. here's the question: "A pilot is required to fly directly from london to rome, in 3.5hours. the displacement is 1400km [S 43degrees E]. a wind is blowing with a velocity of 75km/h [E]...

I have a few questions here, and I'm stuck/confused on some of them. Here they are: 1. The air speed of a small plane is 215 km/h.The wind is blowing at 57 km/h from the west. Determine the velocity of the plane relative to the ground if the pilot keeps the plane aimed in the direction [34...

In an inertial frame of reference, a series of experiments is conducted. In each experiment, two or three forces are applied to an object. The magnitudes of these forces are given. No other forces are acting on the object. In which cases may the object possibly remain at rest? The forces...

Hey, I'm pretty good with all of this stuff... I'm just a bit confused on how to start this one. I mean, usually you begin by figuring out where the reference node is... But I'm not sure what to use as my reference node/ground node... In all the other problems I've done, it's been pretty...

SR is based on the postulate that all physics experiments yield the same results regardless of inertial reference frame? What was Einstein's basis for this assumption? What thought process did he go through to come to that conclusion? How could he know the speed of light was the same...

Does light still travel at c? Thank you.

i hope u can answer these ? for me please 1) how does einstein's special theory of relativity and inertial frames of reference explain and predict the behaviour of natural phenomena (weather)? 2)explain the conservation mass -energy as applied in special relativity? 3) what is the...

Hi, I was thinking about an experiment that might demonstrate frame dragging via the equivalence principle. The apparatus consists of a rotating massive cylindrical shell within a vacuum. Near the inside and the outside of the shell exist two gyroscopes with their axis both...

Hi, I've run into a relativistic kinematics question that I'm not sure how to approach. The question states: "A source and a detector are spaced a certain angle \phi apart on the edge of a rotating disk. The source emits radiation at frequency \omega in it's instantaneous rest frame. What...

under which conditions we could say that the same experiment is performed in different inertial reference frames. I have formulated for myself the following answer: We say that observers from two inertial reference frames perform the same experiment if the physical quantities they measure are...

Frame of reference... Ok here's a question inspired by relativity and frames of reference. In a funfair, there are two carousels (merry-go-rounds), each 4 meters in diameter and their centers 5 meters apart. They revolve with the same angular velocity, but in opposite directions. We have two...

Hi, Please help me, I can't make head or tail of the concept of an inertial reference frame. What is an inertial reference frame? In what fundamental way does it differ from a noninertial reference frame if all motion is relative? Thanks for your help. Molu

Is the comparison of the kinetic energy of a satellite in orbit around the Earth to that of a truck traveling down a road realistic? Are they in the same reference frame?

What is the difference between a frame of refernce and a coordinate system. For example, I know that a rotating frame of reference is non-intertial, but is this also a non-intertial coordinate system? Thanks.

hi, in the case of elastic collision of two balls in constant speeds, if we took the origin in the center of of one of the balls, so the speed of the origin ball will be always zero, and the second ball will has the speed of v befor the collision and -v after the collision. so how the...

i don't know why I am stuck on this question. It seems so easy, its making me sick. question: A man mounts a bathroom scale positioned on a skateboard such that it can roll without friction down an inclined plane of angle theta. He stands on the scale and reads off his weight as he is...

I've been reading Singh's Big Bang book, and towards the end he mentions that the CMBR was used to compute the relative speed of the Milky Way Galaxy, roughly 1,000,000 mph. This seems to suggest that the CMBR can be used as an absolute reference frame for any observer in the universe...

Here is a question one of my physics teachers mentiones a long time ago. Say you have a 10 ft. car and a 10 ft. barn, so the car will just barely fit. Now say the car saw traveling at an appreciable fraction of the speed of light, and you are traveling next to the car, on the line perendicular...

Whats the simplest proof that the Electromagnetic laws are independent of frame of reference? .What I know is contradiction method which einstein also used to conclude the postulate of SR. BJ

Does somebody (i.e. Arildno) know some reference on Asymptotic Matching for Fluid Mechanics equations? I am looking for a good book, but I didn't find nothing in Amazon nor Dover.

hi, can anybody give me any reference material on crabsteering? and the major design parameters involved?

Hi there, I was wondering if somebody knows some nice web page/ book /e book/ resource/ about Pollination and Pollen morphology. I am interested in the big picture of the process, but also paying attention to the different morphologies of pollen grains and its influence on the process. Thanx.

At first I want to know the relationships of the math/formulae on QM and their phylosophical meanings. I've read some books for general public, and have basic idea. So now I'm feeling it's a nice time to learn further. I have some knowledge on electrodynamics (I don't know how much level I...

From the lights point of reference is it traveling infinitly fast? is it's travel instantaneous?

This is a highly theoretical question... so beware! The Work Energy(WE) equation in Mechanics says that the net total work done on an object due to various conservative and non-conservative forces equals the change in kinetic energy of the body. This above theorem is usually derived simply from...

I consider myself a pretty advanced user of Excel, but this one has me stumped. I don't deal with toolbars very often, so I am in uncharted territory. I have a group of macros. At one time, when I ran one of the macros, I realized I had a circular argument and it created an error. No biggie...

Morning :) I am trying to sample two different waveforms, and subtract the one from the other. Basically, I have A, B, and want C=A-B. The device calculating the C=A-B is remote, connected to the two sampling A and B via a wireless link. A and B do not have any common reference or ground, and...

I'll like to buy a reference book. The type of book that has most of the formulas and that kind of stuff. Like for example if I forget a formula, I'll just look it up to refresh my brain. ANyone know any good ones? --thank you.

Hey I am just lookin for some guidance here of what equations to use for this problem. My teacher gave us likea hint, but the hints are from the book used in the previous course and since i am a transfer stuident, i do not have this book. Anyway the question goes as followed... You are...