Frame Definition and 1000 Threads

Let's suppose that I am the Captain at a space dock sitting in interstellar space. My crew decides to go on a trip in our ship, so they board and set off at .9c. t = t0 / sqrt( 1 - v^2/c^2 ), t0 = 1, v = .9c, therefore t = 1 / sqrt( .19 ) = 2.3 (approximately) So as they speed off, 1...

As stated in SR and the principle of equivalence, there is no privileged reference frame or reference frame at absolute rest. However, I went across the following idea that seems to be able to tell if a reference frame is moving or at rest. Please help me point out what is wrong in my idea...

Homework Statement We could change to inertial reference frame in a collision to follow a mass. But what would the down side be if we did? Homework Equations Vf1=(M1-M2)/(M1+M2)*Vi1 +2M2/(M1+M2)*Vi2 Vf2=2M1/(M1+M2)*Vi1 +(M1-M2)/(M1+M2)*Vi2 The Attempt at a Solution This question...

Homework Statement Suppose E and B are measured by an ovserver at rest to be (in N/C) E = [0,0,60] B = [0,0,0] Now another observer travels close by in the +x direction at a constant speed of v = .8c with respect to the other observer. A. What is E' be in the moving frame? DONE b...

Homework Statement In a frame S, two identical particles with electric charge q move abreast along lines parallel to the x-axis, a distance r apart and with velocity v. Determine the force in S that each exerts on the other, by use of the force law for a uniformly moving charge. I would...

I am building a frame that is supposed to resist the highest possible force in the horizontal direction. I am stuck at determining what is the optimal angle at which to design a member that runs against the applied load. In my project the load applied is in the - x direction and the member i am...

The resonating frequency of a series LC circuit is given by: f=(c/2πn)[(dD/Aa)^1/2] This frequency measured in a moving frame is same and hence c is concluded to be constant but the distances and areas may change due to length contaction and the values of inductance and capacitance should not...

Nonlocal entanglement of quantum mechanics suggests the existence of instantaneous communication between distant particles. Related to this, one often hears the following argument: Argument 1: "If the communication is instantaneous in one Lorentz frame, then it is not instantaneous in any...

Homework Statement For the given frame, find the horizontal deflection at the tip of the frame (deflection)C. The frame has a uniform stiffness EI. http://img27.imageshack.us/img27/5493/83214722.png The Attempt at a Solution I don't actually have anything to show, all I want is a hint in the...

I found this nice book on Google http://tinyurl.com/yh2y2zb that does a great job explaining relativity, however, even though the conclusions make perfect sense to me so far, I'm stuck on a conceptual issue when reading over the classic thought experiments that makes me feel like I'm still...

Hello all, Should be a simple question (just started Physics 1 not long ago). Here it is: The thin, fluid filled glass tube is sitting on an accelerating cart. As a result the level of the fluid rises as shown in the picture (attached) by D = 0.6 m. The distance L is given. L = 0.2 m...

Homework Statement I have a sway case beam as in the image below, but do not know the equation for the pinned joints. We were told Moment (AB) = 6EI(delta)/Lsquared for fixed ends such as AB and BA but not told the moment equation for CF for example. I am assuming FC = 0 due to no moment at...

For some reason I've thought about the following case : A uniformly non conductor charged disk is rotating with an angular velocity \vec \omega. If I see it in front of me I'd observe a magnetic field since moving charges produce a current which produce a magnetic field according to Ampere's...

Is it safe to say that any object in an inertial reference frame is at a state of equilibrium? If so.. is it safe to say the opposite: that any object in a state of equilibrium is in an inertial reference frame?

OK, here is an interesting assertion I haven't seen before. Thought I would see what some of the folks here think. The paper is: Quantum Preferred Frame: Does It Really Exist? by J. Rembielinski, K. A. Smolinski (2009) Abstract: "The idea of the preferred frame as a remedy for...

Homework Statement A rocket travels in a straight line with speed 0.6c, where c is the speed of light in a vacuum. A wrist-watch is on board the rocket. The rocket moves past a clock tower on the earth. a. In the inertial frame where the tower is at rest, how long does it take the watch (on...

Hi I'm trying to define a Newtonian lagrangian in an rotating reference frame (with no potential) Something to note is that the time derivative of in a rotating reference frame must be corrected for by: \frac{d {\bf B}}{dt} \rightarrow \frac{d {\bf B}}{dt} + {\bf \omega} \times {\bf...

Is the Change in Rotational Kinetic Energy Frame Invariant? -------------------------------------------------------------------------------- I know the translational kinetic energy of an object is frame dependent. That is, in the center of mass frame of the object, the kinetic energy is...

Sorry if this has been asked, but I did a search and didn't find a relating topic. This thought came to me a few days ago when a friend asked me about time dilation. Time beats slower and distance is shorter for a moving reference frame with respect to a non-moving reference frame, and the...

Homework Statement A picture frame hung against a wall is suspended by two wires attached to its upper corners. If the two wires make the same angle with the vertical, what must this angle be if the tension in each wire is equal to 0.75 of the weight of the frame? (Neglect any friction...

I am confuse of what is inertial frame of reference. Can someone explain that to me? I need a clear explanation starting from the beginning to the end, and if possible, give me some set of example.

What does Special Relativity imply about past, present, and future time? So, here on earth, what can be said about our understanding of past, present, and future actions? Within the same reference frame, is time static? Is it ordered?

Hi guys, I was reading the derivation of ficticious force due to moving frame of reference however i don't understand how they did it.There wasn't detail explanation for slow learners like me so i was wondering does anyone know where i can read up on this or give me some clue where i can start...

Hello Forum, Using a fixed, Cartesian reference frame (i.e., we, observers, are stationary and located at the origin of the system), the trajectory of a particle would be easily described by the parametric (parameter time or arch length) equations [x(t), y(t), z(t)] or [x(s),y(s),z(s)]...

Homework Statement blah blah blah Homework Equations momentum = momentum' mv + mv = (m1+m2)v (Uk)N = friction force The Attempt at a Solution It's hard to find how to start with randomly given values. Thank you so much for your help! :D[SIZE="5"][FONT="Arial Black"][FONT="Arial...

Homework Statement At apparent latitude 45◦N a shell is fired due North at an inclination of 45◦ to the horizontal with initial speed V . Show that, neglecting the curvature of the Earth, the shell will hit the ground at a point a distance \frac{2 \omega V^3}{3g' ^2} East of the line of...

Homework Statement http://img198.imageshack.us/img198/3834/relativeboatvelocity.jpg The note says "( Wind relative to boat is irrelevant! )" Why is it irrelevant?

Frame Analysis Using Method of Members. Determine the force in bar BE. 2. Well, I don't know where to start. I know there are three equations EFy=0, EFx=0, EMc=0 but I don't know what the first member to consider and how to solve this type of problem. There is a final answer given, BE =...

1. Determine the type and magnitude of force in bars BD and BE using method of members. 2. Well, I don't know where to start. I know there are three equations EFy=0, EFx=0, EMc=0 but I don't know what the first member to consider and how to solve this type of problem. 3. There is a hint that...

Could anyone help me on this question: Suppose ${e_i}$ is an orthonormal frame, is $\nabla_{e_1}e_j$ is 0 if i is not equal to j? Any answers or suggestion will be highly appreciated.

If we can shoot a photon outward, at velocity c, why is it that the body that shot it outward is not traveling away from the photon with velocity c?

Is a falling elevator a valid inertial frame? The title about says it. Is a body, (frame) free falling in a gravitational field a valid inertial frame as defined by SR? Thanks

Hi, I was wondering: I'm sitting at my desk and on my desk lies a pen. Does the pen describe a geodesic? And is the room I'm sitting in an inertial frame? I think the pen doesn't describe a geodesic because it's not in free fall and i think my room is a good approximation of an inertial...

Briefly describe a sidereal frame of reference, and then state Newton's laws of motion I can't find sidereal in the index of my textbook, but my googling leads me to conclude that it's something to do with fixed stars. I'm not sure if a sidereal frame is also an inertial frame. Newtons laws...

Hi every one. As Steel Frame Manuel mostly discribe the force analysis in vertical loading, I wonder how can i solve the following case, a member that suffer torison. Is there any reference book you might suggest me to read ,too? Thanks for your kind help. The attached are the cases...

Hi. Say a particle is moving around in uniform circular motion. The way my book attacks this problem is by placing the coordinate system such that one axis is in the radial direction and the other axis is in the tangential direction. Then we have the following for the radial acceleration...

Hi, Myself and my friends fabricated an equipment for electrospinning- a process used used to produce nano fibers. The objective of the work is to get ordered arrangement of nanofibers(we referred a journal). But when it was put to test, it didnt work as expected:-( Please check out the...

Dear PF could you advise me Whether I understand properly or not: In an arbitrary space-time (with an arbitrary curvature) in any sufficiently little region we can go to Local Inertial Frame of Reference - sit into the free falling lift. Being there our experiments are the same as we have...

Hi How do you calculate the natural frequency and vibrational response of a space frame and what is its damping characteristic? What are all the aspects to take into considerations and how do you analyse failure due to vibration? Thanx

Hi all Why do we actually say that Newton's laws do not hold for non inertial frames. can you folks give me an example of how Newton's laws collapse in an non inertial frame(if they do at all)

Homework Statement Hi, I am working on a camera system in flash, and am trying to implement an ease in/out effect where the camera moves between two points, with positive acceleration up to the midpoint, and then negative accelaration up to the end point. I've had a look through the equations...

Hello I'm a visual artist and I'm trying to make a project were I need to add a sound to a photograph hang to a wall in a picture frame.The source of the sound it will be a ipod (unless someone has a better idea)I need to build a device to make the music from the ipod place in the narrow place...

Homework Statement I need to verify a couple of unknown forces in a truss, attached image (all individual trusses are 300mm in length) Homework Equations Determine the forces in trusses shown. The Attempt at a Solution This is a lab and I've used a telescopic gauge with a...

Hi I need help for this structure. It is loaded as shown - point E and G is wheels added as free bearings. I need to know the bending in Beam AD and also EF. I tried isolating beam AD and see it as an statically inderteminant beam to the second degree - but i am not sure this is the right...

Is temperature frame dependent? The temperature of the system is due to the translational,rotational and vibrational movements of the particles of the system Now if a box containing gases at a certain temperature is accelerated the molecules in the direction of motion of the gases get more...

I was thinking about something earlier today. One of Einstein's famous phrases is "I can not believe God plays dice with the Universe." After pondering on this for a while, something confused me. Say for example we have a group of observers who all observed the Simultaniety of an event...

Hey i would really appreciate it if someone could help me with the load calculations in a chassis. The frame is basically a ladder frame, 2 C section side rails and cross members. Would like to know how the weight of the vehicle acting at the Cg gets distributed along the frame. And how does...

Homework Statement Basically, I am looking to find the reaction forces at the pin joint on the right side of the structure. I just realized it is not labeled on my diagram, but it is the pin on the link opposite of E. Where the 13 degree angle is measured from. Homework Equations I have...

hey guys, this may sound dumb, but if it takes an observer to collapse a wave form and create reality, and if the human eye works at about 25 frames per second, does that mean that we only create everything around us every 0.04 seconds? thanks.

collisions and "changing frame of reference?" Homework Statement A 6.0Kg trolley moving at 6.0 m/s right overtakes and collies with a 2kg trolley moving 2m/s right in the same direction on the same track. The collision is cushioned by a perfectly elastic bumper attached to one of the trolleys...