Frame Definition and 1000 Threads

While explaining about inertial and non-inertial frame of reference, people give this example-- http://www.phys.unsw.edu.au/einsteinlight/jw/module1_Inertial.htm if you don't wish to follow the link, here is a simple explanation---> there are two person and a rotating disk. Person A is in...

In this problem we will examine the collision between a baseball (the cowhide) and a bat (the ash). We assume a one-dimensional problem. That is, the bat hits the ball squarely, so that the ball reverses its direction after the collision. We also assume that the ball hits the bat at the center...

Homework Statement A particle of mass M is hanging from one end of a massless spring, while the other is attached to the ceiling of an elevator. The elevator then starts to move upwards at an acceleration equal to g/5. Which way does the equilibrium shift, and what is the magnitude of...

I'm new to the study of SR and GR. I have a question that I have not been able to find any discussion about. In the case of two frames of reference where we are comparing events from the point of view between a 'stationary frame' (inertial) to an excelerating frame like the twin paradox is...

Dear Friends A fleet of spaceships is given, each equipped with a differential microwave radiometer, just like COBE was, whose detectors are antipodeanly pointing (this way one should catch blue shifted radiation and the other one red shifted). Could their acquisitions be used to...

F= q(v x B) B= v x q*k*d/r^2 It is a basic physics knowledge magnetic field forms around moving charge, it tell us magnetic field is zero when charge is not moving and strength of magnetic field increases as velocity increases, right? Magnetic potential vector field increases with "absolute...

In any place of our universe we can define a 'preferred' or 'rest' frame based on the observation of the Cosmic Microwave Background. Of course, in different places of our universe these frames are different, but the idea is the same. If instead of the CMB we define this frame based on the an...

According to the principle of relativity - a postulate for Einstein's SR and GR - any frame of reference is as valid as any other for describing phenomena and the laws of physics will be the same in the chosen frame of reference as in any other frame of reference. Taking the rotating Earth as a...

I am trying to find the force necessary to tilt a vertical frame. I have a triangular frame, which is standing on one of its sides vertically. I am applying a force or around 5 kg's in the horizantal direction on its upper corner. how do i design the frame so that it will not tilt under this...

Hello I have a problem to solve this question in FEM which I apload it here, if you know how to solve this problem can you please help me? Thanks

In every textbook about analytic mechanics, it will give the relation of time derivative of some variable between the space coordinate and body coordinate \left(\dfrac{d\vec{v}}{dt}\right)_{space} = \left(\dfrac{d\vec{v}}{dt}\right)_{body} + \vec{\omega}\times\vec{v} I don't really...

Homework Statement Is a spinning frame of reference an inertial frame of reference? Homework Equations net torque, net force = ma, equilibrium --> net force = 0, net torque = 0 I've learned that an inertial frame of reference is a frame of reference which is not accelerating. The...

Hi All, I am a bit confused about reference frames and inertial frames. According to the first postulate of special relativity (if I'm right), all physical laws take their simplest form in an inertial frame, and there exist multiple inertial frames interrelated by uniform translation...

"Linear frame dragging"? wikipedia at http://en.wikipedia.org/wiki/Frame_Dragging#Frame_dragging_effects says: (Naty1 has drawn attention to this to this in a Library comment.) What is this referring to? Is it a generally accepted terminology, or is it just wikipedia's wishful...

Homework Statement What is an inertial frame of reference? Homework Equations -A particle at rest or moving at a constant velocity in an inertial frame of reference implies that the sum of the forces acting on the particle is zero -The tendency of a body to keep moving once it is set in...

This concept would be dependant on having the technology to actually travel at velocities which we can now, only impart to particles Ie: .99c The plan would be to have 3 ships somewhere in space with negligable gravitational effect. 2 of the ships set out in opposite directions...

In vector calculus, with a space curve C, there are the 3 vectors, tangent, normal, and binormal. Are they always considered in their UNIT form, ie., divided by their length?

since last time i post about the defiinition, i read up about it, how i am still a bit unclear after reading few more post about this topic : einstein: a set of frames which move without acceleration to one another and that the laws of physics hold in the simplest-is the a definition or that...

Hi, I have just been pondering the problem of electron - positron annihilation into a single photon in the CM frame. I was stuck at a discrepancy - that in the center of mass frame, the total momentum of the particles was zero, but the energy is the sum of the energies of the original...

Homework Statement Determine the SUPPORT REACTIONS acting on the frame http://i34.tinypic.com/j94hoo.jpg" You can see I have drawn the FBD, but I am lost on applying static equilibrium about point "F" because I don't know the distance from point "F" to any other point. In order for me to...

Homework Statement Determine the SUPPORT REACTIONS acting on the frame (See Picture Below) You can see I have drawn the FBD, but I am lost on applying static equilibrium about point "F" because I don't know the distance from point "F" to any other point. In order for me to sum the moment...

Homework Statement A red light flashes at position xR = 3:00m and time tR = 1e-9s, and a blue light flashes at xB = 5:00m and tB = 9e-9 s, all measured in the S reference frame. Reference frame S` has its origin at the same point as S at t = t0 = 0; frame S' moves uniformly to the right...

I have heard the following oppinion: Whether a reference frame is inertial is completely determined by whether Newton's laws are applicable for particles moving at low (that is, nonrelativistic) speeds in that reference frame. Do you agree with it?

consider two frames s and s' where s' is moving with velocity vector (0.9c,0,0) with respect to s frame. At time t=t'=0 the origin of the two frames coincide. At time t=2.2x10^-6s a muon decays at coordinates (100,0.8,1.0) meters in the s frame. a) At what time and coordinates does the muon...

I'm currently looking at Metric for the Rain Frame in 'Exploring Black Holes' by Taylor & Wheeler (page B-13) and while it's straightforward understanding drrain (which basically equals dr), I'm having a problem getting my head around dtrain. The following is a step-by-step approach but for some...

I am doing some study about the lorentz transformation between non-inertial frames. I wonder if the tranformation is the same as in SR. I need to do the transformation of EM fields in a constantly rotational frame. Can anybody help me with this one. Is there anybook I can refer to? Many thanks.

The Exodus Frame of Mind Recently David Brooks wrote for the New York Times an article labeled “The Past Meets the Future”. This was an imaginary conversation between Mr. Past and Mr. Future. Mr. Past focused upon our failure to understand the past and in so doing we make egregious...

According to Alice's frame of reference, there is a 1kg object moving through space at 1 m/s along the x coordinate. When x = 0 meters, Alice applies 1 Newton of force to the object in the positive x direction. However, Bob simultaneously applies 1 Newton of force in the opposite direction...

Can anyone tell me whether Wien's law of displacement is valid in Relativistic frame?? Any help would be greatly appreciated. Can u tell me the names of some books dealing with this topic??

hi, g.r speeks of the ability to constract local lorentz frame. how can an observer construct such a frame if spacetime is curved? what are his rods and clocks? it seems that if one tried to construct a "hive" of coords using a ruler, then it will not cross as expected... he might even...

Homework Statement Consider a system of two particles, with masses m1 and m2. What is the ratio of their kinetic energies, T1=T2, in the center-of-mass frame? The Attempt at a Solution I do not really understand the question because center of mass frame was not taught in my class. From...

Homework Statement the question gives me the masses and initial velocities of two balls which collide elastically and asks me to prove that it the momentum will be conserved in both a still reference frame and a moving one. Homework Equations The Attempt at a Solution i know that...

People often have trouble visualizing how time dilation can be "mutual" in special relativity. That is, if you have two clocks moving with respect to each other, in each clock's rest frame the other clock runs slower. The following example illustrates how this can be possible without...

can anybody please clearly explain me the difference between these two frames of reference with few examples. my exames are closing up. please help me.

Suppose an observer is moving at some constant velocity(<< c) and observing the young's double slit experiment. What changes will it observe compared to an observer at rest? This is what i could make out : 1) The wavelength of incoming light will change (doppler effect) 2) By the intuition...

Hey Guys, I've got a pretty simple (I think) pin joint frame question. I am pretty weak in this area of mechanics so if someone could advise me on how to go about doing this question i would really appreciate it. The Figure Q1 (The Attatchment) shows a pin jointed frame. The frame is...

Problem If you throw a ball with velocity v at a wall, it rebounds with the same speed, v. What happens if you throw it at speed v towards a wall which is traveling towards you at speed w? What is your answer in the limit in which w is much larger than v? Answer Let us work in the frame of...

Hi, I have been working on a MATLAB program for solving the member forces in a 2d frame structure which many people have helped me out with on this forum. I have finally got the script to a point where it is working ok and have shown the command window output for a solving a simple frame. My...

Why is it conventional to analyse compton scattering in the lab frame (fixed target) whereas all other processes I've seen are analysed in the center of momentum (colliding beam) frame. Are there any experiments where one would collide electrons with stationary muons e.g.?

I'm not sure if either Einstein or Newton said that all frame of reference are equally valid. That from my point of view, the laws of physics is the same from your point of view. All frame reference can be put on an equal footing. I was wondering, can one consider the geocentric view that the...

According to Einstein, there is no absolute frame of reference; no such thing as 'absolute rest'. But does not the Cosmic Background Radiation provide an absolute frame of reference? An object for which this radiation is totally isotropic is at absolute rest; I gather we move relative to it at...

Hi Pervect, You concluded the thread titled “Another question about photon perspective, concerning entanglement” initiated by Anticitizen with this post: You also concluded the thread titled “Reference frame of Light” initiated by Klotz with this post: I am having difficulty...

Hi, I had a question on CG. I have a rectangular frame (say made of square tubes) and have a weight fastened to its lower arm (as shown in the attached pic.), which is not fastened on the center of the lower arm but is offset. however, the CG of the weight is in the same line as the pick...

Hi, I'm quite new to relativity and I'm just going through some problems from past exam papers to prepare for an upcoming subject. The following question has me a little stumped: Betty is at the origin of her frame of reference. At a certain point in time, this also corresponds to the...

Is there some way to define an inertial coordinate system without being cyclical (defining it with terms that require an inertial coordinate system to define)? For example if you refer to straight lines... straight according to what coordinate system? Or if you refer to velocity... that...

How can you have an inertial reference frame in which a body can remain at rest or move with constant velocity unless you postulate the disappearance of the universe? In the Michelson Morley experiment the Earth is not moving with constant velocity, it is accelerating. So the postulates of...

In regard of frame-dragging within the ergosphere of a rotating black hole, what effect would this have on gravity? It seems accepted that with frame dragging (or lense-thirring), the fabric of space is dragged around with the black hole but that light within the ergosphere still travels at...

I'm not sure this is the right place to post this question but here goes: In feynman vol.1 39-9 there is a situation where two molecules are about to collide in a CM frame, the frame has velocity Vcm and the two molecules have respective velocities v1 and v2, then there is no correlation...

I am reading Taylor and Wheeler's Spacetime Physics. I am enjoying it a lot and find it extremely readable but I have a question regarding something. I am not sure how to determine the dimensions of a frame necessary for it to be called a free float frame. This is a general question I know. To...

I have scanned the simultaneity related posts and cannot find a succinct answer to a question I have - I accept that the answer is probably buried in one or more of them. My question is related to the common claim that you somehow lose simultaneity in relativity, or that the idea of...