Frame Definition and 1000 Threads

Homework Statement I am currently embarking on a project which requires me to design a system where I can transmit voice over a distance, by inputting an analog voice signal on one end and then recovering the voice which I input on the transmitting end at the receiving end. The general design...

I'm studying special relativity for the second time and there's something I think I didn't get since I studied classical mechanics: the idea of a frame of reference. I think the underlying idea is that of a point of view, so that we want to study some phenomenon, but we have to observe it so...

In analysis of frames, we say that "The members of the frames are axially inextensible". In context of frames with vertical legs, what I understand is that the length of the chord joining the member ends in the displaced condition would be same in the axial direction. However, what does it imply...

I had asked this about 2 years ago - but for the life of me cannot find it. Please feel free to cancel this if you can find my OP. Anyhow my question was this: A "train" passes by at significant relativistic speed, along the "x" axis. "Platform" observer peers in windows of train as it passes...

So I understand that in classical physics, movement only makes sense with reference to another body. So my car moves relative to the surface of the road, for example. But it seems that with acceleration, things appear to be more complicated than that. Let's say we have two objects in space...

Homework Statement Hi, I need some help analysing this frame. First of all i bellive its hard, if not impossible, to get as detailed results by hand calculations as my softwear CSI Sap2000. Becourse of shear and axial deformation. Is it possible to obtain the stiffness matrix of this frame at...

First time posting in this section. I understand that this question could possibly be an old and common question about Lorentz Transformation, however I failed to find useful discussions or instructions online. Assuming that there're 2 frames ##S, S'## where ##S'## moves along the ##x_{+}##...

Hi all, I'm having trouble with the concept of a co-moving frame, specifically in the context of constant proper-acceleration (hyperbolic motion). I feel like I don't "get it"; and perhaps this is related to some deeper misunderstandings I may have regarding the definitions of certain quantities...

Let say a plane flights at 1km/s, shoots a 2kg projectile at 1km/s, so to the Earth, the projectile flights at 2km/s with 2*2*2/2 = 4MJ. The same gun when fixed on Earth, shoots the same 2kg projectile at 1km/s, achieves 2*1*1/2 = 1MJ Assume that the energy comes from burning propellant or...

You are standing on one. The two planets were closing in on a speed of 1x. You just accelerated one of the 2 planets towards the other with a super powerful rocket engine, and then sat on one of them. Now they are closing in on each other at speed 10x. The universe is otherwhise empty. The...

Homework Statement The question is: A simple pendulum is mounted in an elevator. What happens to the period of the pendulum (does it increase, decrease, or remain the same) if the elevator (a) accelerates upward at 5 m/s/s (b) moves upward at a steady 5 m/s (c) accelerates downward at 5 m/s/s...

Homework Statement The problem I have is not actually so much a physics problem but more of a logical problem. When we look at rulers and any kind of measuring tools, we start from zero. We count the number of intervals instead of the divisions. Suppose we have a video with 7 frames per...

We know that when a rigid frame, say a rocket undergoes constant proper acceleration, its worldline is hyperbolic. The equation is given by: x^2 - c^2t^2 = \left( \frac{c^2}{a_0} \right)^2 Suppose P is such a worldline and worldine can also be written as: I understand how these are...

1. The problem statement, equations, and work done: [A] Two identical spring and mass oscillators are set in motion in perpendicular directions. The masses are each 4.0 kg and the spring constants are 196 N/m. [1] Calculate the angular frequency and the period of the oscillators. ##\omega =...

Hello, my problem is as follows I've tried finding the invariant mass of the positron and pion as follows M^2=(E_e+E_{\pi})^2-(\mathbf{p_e}+\mathbf{p_{\pi}})\\ =E_e^2+E_{\pi}^2+2E_eE_{\pi}-p_e^2-p_{\pi}^2-2\mathbf{p_ep_{\pi}}\\ =m_e^2+m_{\pi}^2-2(E_eE_{\pi}+\mathbf{p_ep_{\pi}})\\...

Homework Statement Given incoming photon has energy 10Mev and scatters at angle 25 degrees, find the scattering angle in CM frame. Homework EquationsThe Attempt at a Solution [/B] In lab frame, let the energy of incoming photon be ##E##. Total 4-vector would be ##P + Q =...

If you have a car and a pendulum is hanged inside it, and if you watch from outside the car,and if the car has some acceleration, then you see the bob moving in opposite direction of motion of car. For a person standing outside, he knows that the car has some acceleration. What causes the bob...

Homework Statement I am trying to find a local inertial frame for the following metric: ds^2 = -(1+\Phi(x))dt^2 + (1-\Phi(x))dx^2 I can get the transformed metric to equate to η at any point, but I can't get the first derivates wrt the transformed coordinates to vanish. Homework Equations...

Homework Statement Hello. I've created a small program to find shear and bending diagrams of the members of a frame. I was able to get the reactions at the support but don't know how to continue from now. This is an example of a frame all columns are 3m in height and the beams 8m. All the beams...

Alright so I'm still trying to get a hang of the theories of relativity, and this thing has really been bugging me. All forms of motion (and sometimes even physical observations) are defined for a particular local frame of reference. But is there any "stationary" frame of reference in the...

I am using an algorithm that transforms from my sensor frame to North West Up and I want to instead use North East Down. I have attached the current algorithm. I also want to skip the first step in my algorithm. Here is the current algorithm: http://www.filedropper.com/transformationalgorithm...

Hello. I have a project for next semester and I'm thinking of creating a program using mathematica to analyze a concrete frame to obtain the moment and shear diagram. What would you consider the best method for analysis. The loads will be uniformly distributed. Any tip will be greatly...

Hello, I was wondering about a question and how it would be reconciled within Newton's laws of motion. Take a case where two boxes are stacked on top of each other, and the bottom box rests on a frictionless surface. Now, imagine a rope is attached to the top box, and tension is applied to...

Hi I am trying to understand more about these terms. I am currently studying a course about relativity and cosmology, but I am finding the textbook (Open University) difficult to follow. Can anyone help me untangle and make some simple sense of these different terms? Thanks (I accidentally...

Hi I am trying to understand more about these terms. I am currently studying a course about relativity and cosmology, but I am finding the textbook (Open University) difficult to follow. Can anyone help me untangle and make some simple sense of these different terms? Thanks

In all the places where Spin-Orbit interaction is discussed, the equations are derived by going to electron's rest frame and considering the interaction of nucleus' magnetic field with electrons spin magnetic moment. But from SR, we know that there as to be an explantion from the nucleus's rest...

Can you use a vacuum, or lighter than air gas within a tubular frame network to neutralize the apparent weight of the frame? If this is possible what is thee smallest possible size you could make this frame, I understand that the more you scale it up the lighter proportionately the frame would...

Hello, I have a Hamiltonian that describes a particle in a rotating cylindrical container at angular frequency ω. In the lab frame the Hamiltonian is time-dependent and takes the form (using cylindrical coordinates) \mathcal H_o=\frac{\vec P^2}{2m}+V(r,\theta-\omega t,z), where V(r,\theta,z)...

My apologies for the numerous times this has probably been posted, but I wasn't able to find a great answer through the search tool alone. Please correct me on anything I state incorrectly, and direct me to the answer.. My question is, if the speed of light is 299,792,458 m/s, its speed is...

Greetings, Here is my question: What is the difference between the labframe and the center of mass frame in QM scattering theory? Is it that in the labframe both particles are moving towards each other and in the center of mass frame one particle is static and a second one is moving towards the...

Our sun rotates in counter clockwise direction and hence frame dragging will be also in that direction. Suppose if we put a satellite in sun's orbit (almost circular) to revolve in opposite direction to the sun's spin, what would happen to the orbit of the satellite? Would it fall into the sun?

I've managed to get through all of this question without trouble until part d). The full question is given here: I've calculated the "true" angles of Star A and Star B as 71.57 degrees and 45 degrees respectively in Frame S, and the "light" angles should be the same, since the stars are...

Homework Statement Not a homework or coursework question, but given the simplicity of the problem I feel that this is an appropriate subforum. Consider a person spinning a rock on a string above their head at a constant angular velocity, walking away from the observer at a constant linear...

So, from what I understand, quantum uncertainty means these vacuum fluctuations occur, and out of them come virtual particle and antiparticle pairs. How does this not create a preferred frame of reference? A particular particle pair must have a certain amount of energy, and in one frame where...

Homework Statement Hi, I have an exercise where we are supposed to find a condition for which two clocks are synchronise if one clock is accelerated. Homework Equations The time dilation in an inertial frame moving with velocity v is well known. t'=\frac{t}{1-\frac{v^2}{c^2}} The Attempt at a...

Hello. I need help with the following problem: I don't know where to start. I know that the frame can be split up into one symmetric part and one symmetric+assymetric part but i forgot the theory and rules on translation and axis etc. I hope someone can help as I have to hand in the...

I already have the solutions emailed to me from a D H Lawden textbook. I have trouble understanding the solution as the solution is not formatted properly, and the answer seems to be a little too advanced for me. I hope that some one can help me understand the problem. 1. Homework Statement...

Homework Statement Anna and Bob have identical meter sticks. Anna an observer on Earth, sees Bob traveling in a spaceship at 0.5c away from her. Bob leaves his spaceship in an escape pod, moving away from Earth and the spaceship at 0.1c with respect to the spaceship. How long is Bob's meter...

I apologize if this has been discussed before. I am no physicist, I am just trying to see if I am understanding special relativity correctly. Please be advised I am dumb, so be gentle. If a spaceship (sorry for the cliché, but it's a little bit cumbersome to keep using the phrase "inertial...

Find the optimum frame length nf that maximizes transmission efficiency for a channel with random bit erros by taking the derivative and setting it to zero for the following protocols: (a) Stop-and-Wait ARQ (b) Go-Back-N ARQ (c) Selective Repeat ARQ My work has been uploaded I am a bit rusty on...

If a metallic ball is place inside a giant hollow top, and the top starts to rotate. Along with the top, the metallic ball will also start to rotate. Thus my question is the ball motion is under inertial frame of reference or non-inertial ?

Is thermodynamics states like temperature, pressure and material properties like specific heat, thermal conductivity etc. invariant with inertial reference frame?.

If a metallic ball is place under a giant hollow top, and the top starts to rotate. Along with the top, the metallic ball will also start to rotate. Thus my question is the ball motion is under inertial frame of reference or non-inertial ?

Okay guys, I still feel like I don't quite understand these concepts well enough. Do you guys have any websites or links to help me understand these concepts better? I feel like I only partially understand these concepts. I also feel like I partially understand the application of the mathematics...

I'm wondering if someone is observing a situation from a frame moving in a uniform circular motion, would that frame of reference be considered inertial? I'm unsure because of the centripetal acceleration towards the center.

Hello, I noticed quite a few questions on the Hafele-Keating experiment here, but I believe none that have my exact question. I understand the explanation given for "a frame of reference at rest with respect to the center of the earth", as in the Wikipedia article. But what happens if...

The Schwarzschild Metric has a form: ##ds^2 = Kdt^2 - 1/K dr^2 - r^2dO^2## where: K = 1 - a/r; There is a time scaled by K, but a space radially by 1/K. This is a typical time dilation and a space contraction, which is known from SR, but the Schwarzschild metrics is spherically...

Einstein tensor in the FLRW frame - Part 1 of 2 This note develops a formula for the ##G^{00}## component of the Einstein tensor in the FLRW coordinate system for a homogeneous and isotropic spacetime. We use the convention that tensor indices ##i, j## or ##k## are used only for spatial...

If there were only one rotating massive body and a detector in the universe, would the detector be able to detect that body due to frame dragging, i am imagining the body acting on granular space time akin to a whirlpool, were space time is disturbed in a spiral motion. I am not talking about...

I confuse when should I use non-inertial frame... is there any keyword or key clues that remind you of using non-inertial frame of reference? can anyone help explain this with an example?