Inertial frame Definition and 128 Threads

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...

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?

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...

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.

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...

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 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)

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...

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...

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...

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...

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...

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...

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...

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'm sorry, this topic has certainly already been covered, but I didn't find what I need. I'm trying to compute x(t) in an inertial frame if a rocket has a constant acceleration "a" as measured with accelerometers inside of it. I made these (clearly wrong) computations: In a co-moving...

I was reading a physics textbook. It is stated that force is defined by mass and acceleration (a force of 1N causes a mass of 1kg to accelerate at 1ms^-2). In later part, it is stated that mass is defined by force and acceleration (a mass acted by a force of 1N accelerates at 1ms^-2 is 1kg). As...

what is an inertial frame of reference ? Simple ?

What forces affect on the Moon in the Inertial frame of reference which is the Sun? +gravity form the Sun +gravity from the Earth +centrifugal force from the rotationary movement of the Moon round the Earth is this list correct?

Homework Statement How can i define a perfectly inertial frame ?

Homework Statement An inertial frame R in which the particles’ positions and velocities are related by A1= - m2 (A2) / m1 V1 = - m2(V2) / m1 at time t = 0. Show that these relationships persist at all subsequent times. Homework Equations The Attempt at a Solution...

Suppose that we choose an inertial frame R in which the particles’ positions and velocities are related by A1= - m2 (A2) / m1 V1 = - m2(V2) / m1 at time t = 0. Show that these relationships persist at all subsequent times.

So I've been working on this problem. I am given the metric in Kruskal coordinates, so ds^2=32M^2exp(-r/2M)/r(-dT^2+dX^2)+r^2(dθ^2+sin^2(θ)dΦ^2) And the path of a particle is X=0 T=λ θ=π/2 Φ=0 And the path of the observer is X=-1/2*T+1/2 θ=π/2 Φ=0 And I am asked to find the 3...

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...

Does the speed of light for an observer falling into a black-hole remain the same?

dear friends, i have one problem regarding the inertial frames.it is said that freely falling elevator satisfies the above property.if there are two particles inside the elevator the distance betn. them will remain same as long as the distance is small.but when the distance betn. the paricles...

I wasn't sure whether to post this in the classical or relativity section. While pondering something I found an embarrassing gap in my knowledge. I can't quite get my head around this problem and I need a fresh perspective. Consider two beams of electrons moving parallel to each other. The...