Frame Definition and 1000 Threads

So, I need to make an Excel spreadsheet that realistically models the motion of a toy rocket. I need to take drag, gravity, and thrust into account, keeping in mind that the latter two will be influenced by the change in mass. The equation for force I must use, then, is: F = ma + v(dm/dt)...

Homework Statement A cylinder rotating uniformly about the x' axis of S' will seem twisted when observed instantaneously in S, where it not only rotates but also travels forward. If the angular speed of the cylinder in S' is ω, prove that in S the twist per unit length is yωv/c(squared)...

Hey guys, I am having some problems with the concept of inertial/non-inertial frames of reference and their applications in engineering dynamics. So I've learned that a given frame of reference is defined to be non-inertial when something in the studied system can only be explained through...

Ok, so I don't have much of an intuition for frame bundles, so I have some basic questions. A frame bundle over a manifold M is a principle bundle who's fibers are the sets of ordered bases for the vector fields on M right. 1) This means that any point in the fiber (say, over a point m in M)...

Hello, Suppose, A and B is clocks at both end of train. A is at left and B is at right. Observer O is at middle of train at point M. Observer R is on platform. Train is at rest and O synchronize both clock. The clock is synchronized with respect to both observer. Now, train starts moving to...

According to this, if someone spins around at 2 revs per second when the moon is in the horizon, the moon seems to move at 4 times the speed of light. And this implies the moon is not in our local reference frame. And per this, local inertial frame applies to "small regions of a gravitational...

Would it be possible that every rest frame is going through a force field so everything will be smaller on atom level and time goes slower too (Lorentz, Einstein) ? So that force field is the holder of the encapsulated ration distance / time (C) ... That would explain the unknown time...

Homework Statement The electron is traveling at a speed of β=.9999999, γ=1957, with mass mc^2=.51099 MeV. The Proton is traveling at a speed of β=.9, γ=2.29, with mass mc^2=938.27 MeV. They are heading in opposite directions, directly towards each other on the x-axis Find the reference...

If you a mass being accelerated by a force which is acting upon a spring attached to the mass it will exhibit harmonic motion. However unlike a fixed harmonic oscillator there is no explicit solution to the equation which describes the motion of the mass in a reference frame outside of the...

Lets say for a moment that everything that travels at speed below c has a rest frame.. All kinds of waves are produced from entities which has a rest frame... for example, Water waves produced from water surface which has a rest frame, similarly sound waves from physical objects, light...

Hello, I've seen spin orbit coupling being explained by going to the rest frame of the electron and noting that the proton is then a moving charge and hence has a magnetic field, which interacts with the spin of the electron, effectively coupling the spin and angular momentum of the electron...

Homework Statement events A(ct,x)=(1m, 2m) and B(ct,x)=(3m,4m) are separated in a lightlike interval. I need to find the velocity of a separate reference frame in which they BOTH occur at the same time. Next I need to find the velocity of the frame where they will occur at the same...

Do galaxies produce measurable/significant frame dragging effects by their rotation? I would think frame dragging depends on the mass and speed of rotation... Are such effects only felt at the boundary between rotating gravitational fields and flatter space, i.e. the edge of the milky way? Or...

Hello my name is Donald. I need some help analysing a frame for equilibrium at the joints. I will attach a drawing of the work I have performed so-far. I am stuck where the brace meets the right post at 2.5 ft. from top. This is my first try at posting, please forgive me for lack of knowledge...

As stated in SR, mass of the object increases with its velocity right? Lets assume that all the objects in the universe have consciousness and they all know what their rest mass is...(Leave photons out of the argument).. And also assume they all can measure their own mass at any instant...

I've just found out that in the centre of mass frame, the angle of deflection in a collision is different from in the lab frame. I vaguely understand why: if the frame you viewed the particles in was also moving but only horizontally it would make their horizontal movement appear to decrease...

Can someone give me a clue/hint to finish this question? "In a reference frame S, the electric and magnetic fields of an electromagnetic wave E and B are perpendicular to each other. Determine the velocity of a reference frame S' in which (a) E' = 0 and (b) B' = 0"

Hi. Ok, so I'm trying to understand the "navigation equations". n: frame traveling on Earth with vehicle. e: frame centered in earth, rotating with it. P: Position of vehicle center of gravity. v^{n}_{P/e} = (vn,ve,vd): velocity of P w.r.t to e-frame, expressed in n-frame. Normally...

A question please in three parts, need the numbers for the first before I can asked the next. A Machine lowers from rest, 100 pounds under control, at 2m/s, for 1000mm. Then immediately stops the weight, and lifts it back up at 2m/s. At the transition from negative to positive, what...

I found out that Proxima Centauri is 4.2 light years away from earth. If someone was on a voyage to this star via space ship, would this person measure the time to be shorter than 4.2 years if their spaceship was traveling 99.99999 percent the speed of light, assuming that the 4.2 years is...

Is this correct? There are two clocks on Earth that are synchronized. One clock goes out on a spaceship at .8c. Now according to the stationary or Earth FOR one year goes by for its clock but he sees that only .6 of a year has gone by on the clock of the spaceship. Now the spaceship...

So what will it see it self as?? At rest or moving a velocity c? Either way it seems to be a contradiction, so does that mean a photon can't be reference frame?

Last thread that I initiated was titled `Simultaneity is directional while Time Dilation is not', which presented a scenario for the Non-directional property of Time Dilation in STR. Which I think, needs to be reconsidered. And I believe this is the reason why `STR can only be worked out when we...

Hi there, I was doing some calculations with tensors and ran into a result which seems a bit odd to me. I hope someone can validate this or tell me where my mistake is. So I have a normal orthonormal frame field \{E_i\} in the neighbourhood of a point p in a Riemannian manifold (M,g), i.e...

Please excuse my ignorance - I am a biologist by training - but this is one of those questions that just keeps bothering me and I can't find the answer with Google/Wikipedia. Take as our example the ocean currents on the Earth caused by the Coriolis Effect of the Earth turning. When I read up...

I have been reading Einsteins Relativity and a simple concept in special relativity is tripping me up. I have heard that an object can never reach the speed of light. To which observer is this speed limit seen by. I know your answer will be "By all observers" but that is what I don't get...

I have asked similar before, however I don’t think I was going about asking it right, as I never got a fulfilling answer. Both Men are equal in all ways, their 1RM {repetition maximum, or the maximum they can pick up once is 100 pounds} Reps = repetitions. .5/.5 or similar means the rep took...

We normally assume that the recession of distant galaxies is due to the expansion of the space between the galaxies and us. In a co-moving frame the expansion of space is factored out so that all objects remain at a fixed distance away from us in cosmological time. Thus the co-moving frame is...

A Newtonian inertial frame is one where objects obey Newton's first law. Schutz (A first course in general relativity) says an inertial frame cannot be constructed in a gravitational field because it's then impossible to synchronize the frame's clocks? For the same reason an inertial frame...

When one says they are at rest relative to the cosmic microwave background, does this mean that they are in a frame where the same frequency is measureed in all directions? Because, I could imagine if I boosted in one direction, then the spectrum behind me would be redshifted, and the spectrum...

The experts say the age of the universe is known with considerable accuracy. What frame of reference are they using and why doesn't it violate the idea of relativity to claim to have a preferred frame?

- http://www.physicsinsights.org/glossary.html I'm often unsure whether people are using "frame" to mean a chart, or a basis field of tangent vectors, or a basis for an individual tangent space. Have I got this (more or less) right? (1) A MCRF of a pointlike object is a function that...

Is there really an absolute reference frame?? According to mechanics as we understand today, all reference frames are equally valid in analysing in the universe, whether measurements are taken relative to the earth/sun... However if all reference frames are equal, why can't we take...

Hi All! I found discussions on this here while researching the subject to see if anyone else has attempted to explore the subject. I saw that several people asked questions pertaining to this, but the question was never really answered. It seemed unanswerable. While many discussions of...

Homework Statement A double pendulum consists of two particles of equal mass m suspended by massless rods of equal length l. Assuming that all motion is in a vertical plane: 1. Find the Lagrangian of this system. 2. then find the equations of motion and, 3. linearize these equations...

I was wondering if say.. you have a particle moving at 0.5c in the +x direction and a lightbulb at relative rest to the particle. The particle passes the lightbulb at t_{0} The lightbulb then flashes, the wave reaches the particle at a particular point, and the speed of light is then measured...

Homework Statement Consider the bead threaded on a cicular hoop of example 7.6 (pg 260), working in a frame that rotates with the hoop. find the equation of motion of the bead, and check that your result agrees with eq 7. 69. Using a free body diagram explain the result 7.71 for...

Gentlemen, I am needing help choosing the correct materials to construct a stationary 'A' frame crane with a fixed radius of 15ft, back stayed with 2-1" cables approx. 70ft behind main non-rotational boom legs attached to embedded concrete weights, height of boom is 60 ft with pendants...

Basically I want to understand what Rindler observer will see if he looks out the window in direction that is perpendicular to direction of acceleration. As I understand there are at least three effects (as analyzed from perspective of Minkowski observer): 1) accelerated motion relative to...

Hi! :smile: Need some help here. Can we perceive time dilation and length contraction in a non-inertial reference frame? If we observe a reference frame experiencing acceleration close to c, do we see the same effects as in an inertial reference frame?

Homework Statement You are in a train traveling on a horizontal track and notice that a iece of luggage starts to slide toward the front of the train. from this observation you can conclude that this train is not an inertial reference frame because it is slowing down. Homework Equations...

Problems related to conservation of momentum/energy can be solved by taking reference frame which is stationary to center of mass or which is stationary to ground/observer. So when to use what frame or which frame is beneficial in which case/type of problems? I m confused !:confused:

Breit Frame of reference ("Brick Wall") I am having a lot of trouble understanding breit frame of reference.I was trying to solve griffiths problem 3.21 (1st ed.): Consider elastic scattering- A+B----->A+B If particle A carries energy E, and scatters at an angle theta in the CM, a) what is...

Can the kinetic friction be in the direction of acceleration? I am thinking of the example of a box on a flatbed truck accelerating to the right from rest. The box accelerates to the left due to the inertial force as seen by an observer on the truck where the kinetic friction is opposite to the...

Suppose, in the first case, that an object (initially at rest in frame S) accelerates, for whatever reason upward, with a force F. Let M be the relativistic mass of the object. The force measured in frame S is relativistically given by: F_s=γ^2...

this thought was inspired by the recent news about FTL neutrinos. of course i suspect their instruments are broken and that no such thing happened, but regardless, the question stands: it's easy to talk about the rest frame of classical objects where the notion of "trajectory" applies and...

Please bring me out of my state of confusion if I need to be... The question is how to calculate the rate of an atomic clock (a pendulum clock may work otherwise) on board a vehicle traveling along the surface of the Earth at constant altitude, like a bus, a train or an aeroplane. This was first...

To compute the checksum for some frame with m bits, corresponding to the polynomial M(x), the frame must be longer than the generator polynomial. Why...?

I have a question I wanted to clear up. According to the definition of a "local inertial" frame in GR, you must use a coordinate system that locally looks Cartesian, right? I mean if you had a coordinate system with a basis that wasn't orthogonal, then it would not be considered a local inertial...

Here is a link to the problem: http://img62.imageshack.us/img62/374/frameow.jpg" I am trying to find the support reactions at A and B. I separated the frame at the hinge(call it C) into two parts and took the moment equation about point A. This gave me: \SigmaMa = -60(25) - 62.5(12.5) +...