Inertial Definition and 500 Threads

I have a small intuitive issue with the idea. If you could humour me for a moment, imagine a particle moving at some velocity v. An observer sitting on an armchair at rest wrt the background stars, but far enough away from them to negate any gravitational effects, sees the particle moving...

An interesting idea that my physics teacher posed to us yesterday, and apparently one that scientists have been puzzling over for quite a while: why is the mass as a measure of inertia equal to the mass in terms of gravity in our universe? My teacher said that this doesn't need to be the case...

Ok, so I've been thinking of a certain paradox in relativity that I can't seem to resolve: We have two observers, one in a "stationary" frame outside the Earth. This observer is looking down on Earth at another observer sitting at rest with respect to the surface of the Earth, but obviously...

Hi, I just finished class and my professor was writing some of Newton's Laws on the board and derived some equations. We ended up with: V(Δt)=FΔt (this is for velocity in first inertial frame V(2Δt)=2FΔt (this is for velocity in second inertial frame Then he went and got the position in...

Hi everyone ! Which are the major properties of inertial forces ?

Hi everyone! In an university examination it was asked to:"Explain the difference between inertial and gravitational mass" but my physics book is not very exhaustive on these differences. Which could it be a precise answer to this question ?

Hi to all, I am a new one to this physics forum and i have a doubt regarding Inertial Reference frames. In an article of IRF, it is given as "There is no absolute inertial reference frame, meaning that there is no state of velocity which is special in the universe." Can anybody please...

It's a standard fact of GR that at a given point in space-time, we can construct a coordinate system such that the metric tensor takes the form of Minkowski spacetime and its first derivatives vanish. Equivalently, we can make the Christoffel symbols vanish at point. Moreover, the fact that, in...

This question has been bugging me for a while now. I roughly understand how the Higgs mechanism gives elementary particles their rest mass and I also understand that gravity couples to all forms of energy, including binding energy in a nucleus or atom. I also know most of the mass of a system...

Hi there. I need help to work this out. A particle with mass m is studied over a rotating reference frame, which rotates along the OZ axis with angular velocity \dot\phi=\omega, directed along OZ. It is possible to prove that the potential (due to inertial forces) can be written as: V=\omega...

i was looking at the lorentz dilation and contractions for SR. My books says they are \grave{l}=l\gamma and that \grave{t}=\frac{t}{\gamma} .what i don't understand is that the velocity in the unprimed system is then \frac{l}{t} but in the primed system its \frac{l\gamma^{2}}{t} which is not...

Please explain the concept of pseudo forces by considering an example of two cars say A and B, accelerating in the same direction. How will Newton's law applied to the man in car B as noted by the man in car A differs from that of the man standing on the earth? And how will the man in car A...

I have no background in relativity. Recently I started reading some introduction to special relativity in Griffith's EM book, where he vaguely defined an inertial reference frame as one in which Newton's first law holds. Now according to this definition, does such frame exist in nature? On...

By the equivalence principle, the gravitational mass of light is its inertial mass, which it has because it has momentum. Light can impart some of its the momentum to massive objects, upon which it will lose energy, which is manifested by its frequency (the basic principle behind doppler...

Need help understanding inertial frames of reference! I'm doing an A2 physics unit on special relativity (AQA) and am really confused about this, but I only want to get the idea so don't go to deep please :) I understand that a frame of reference is an area which is fixed relative to...

Homework Statement Specify and explain whether the following is an inertial or non-inertial observer: An observer is placed on a rock between Andromeda and the Milky Way. Homework Equations N/a The Attempt at a Solution So here is my understanding, the observer would be situated...

People tell me that we cannot extend our inertial frame, as defined in special relativity, across the Universe because that would be in violation of general relativity. The problem is that general relativity says that space-time can be curved whereas a global inertial frame assumes flat...

We know that we can't say whether we are at rest or uniformly moving if we're in a einstein cage..but if the same medium is accelerating/decelerating can we being inside(and can't see outside) claim abt state of cage..?I ve read that a non-inertial can be converted to inertial by incorporating a...

Hi, I have a couple of questions about velocities in inertial and rotating frames of reference, related by the following equation: \mathbf{v_i} \ \stackrel{\mathrm{def}}{=}\ \frac{d\mathbf{r}}{dt} = \left( \frac{d\mathbf{r}}{dt} \right)_{\mathrm{r}} + \boldsymbol\Omega \times...

i know these topics are discussed many times and i have read many of them but still have a doubt. Suppose a car is accelerating and there is an object and a man in the car. Object is ofcourse at rest with respect to man. The man does not know if the car is accelerating or not - he just sees...

Homework Statement A rod lies at an angle α with the x'-axis of an inertial frame moving at a speed v along the x-axis(x and x' are parallel) of another inertial frame. The rod makes angle β with the x-axis of this frame. Find the relation between α and β. Variables: α,β,v and define...

Newton's second law of motion is given in Minkowski space by \bar{F}=m(c\gamma\dot{\gamma}, \gamma\dot{\gamma}\tilde{v}+\gamma^{2}\tilde{a}) where \dot{\gamma}=\frac{d\gamma}{dt}=\frac{\gamma^{3}}{c^{2}}\tilde{v}\cdot\tilde{a} and \tilde{v}(t) and \tilde{a}(t) the 3-velocity and...

A charged particle is placed next to a current-carrying wire. The wire produces a magnetic field, but if the particle is at rest, the field exerts no force on it. However, in a different inertial reference frame moving at speed v parallel to the wire, the particle is seen to be in motion, and so...

Hi, This is partly inspired by the questions in the thread about normal forces on a cornering car but I thought I'd post here instead of mix that thread up with my question. So suppose we have a biker leaning into a corner. There are the normal force and the force of friction which act at the...

Hello, I am having difficulty understanding the concept of Newton's first law only applying in an inertial reference frame, or a frame that is at constant velocity, however, apparently the 1st law no longer applies if the reference frame is accelerating. Can anyone give me some sort of concrete...

Homework Statement In the Home Frame, two events are observed to occur with a spatial separation of 12ns and a time coordination separation of 24ns. A)An inertial clock travels between these events in such a manner as to be present at both events. What timer interval does this clock read...

The initial presentation of Newton’s Laws of Motion (NLM) to students often proceeds as follow: 1. The 3 laws are presented, 2. The caveat that the laws are only valid in Inertial Reference Frames (IRFs) is (sheepishly) mentioned, 3. An attempt is made to define an IRF, and 4. Some examples...

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...

As a result of observations made over many, many years, physicists have inferred that: "No experimental test provides any way to distinguish an inertial frame from another." This negative form of the statement is important, as it is a prediction which can be tested experimentally and thus...

So this is problem 11.1 out of Jackson Electrodynamics: Two equivalent intertial frames K and K' are such that K' moves in the positive x direction with speed v as seen from K. The spatial coordinate axes in K' are parallel to those in K and the two origins are coincident at times t=t'=0. (a)...

Does time period of SHM vary with frame(inertial and non inertial)?? Homework Statement There is an SHM. First observer is watching it from inertial frame of refrence and secodn is from non inertial will there any change of time period for both observer. Homework Equations just think...

In a 1925 paper, Erwin Schrödinger mentions that "our inertial systems are free of rotation precisely with respect to our stellar system", instead of being "anchored...in much more distant stellar masses". Is this really the case? If so, this suggests that the total gravitational potential...

Dear :), could some one please guide me in the right direction to answer the following questions: 1) using MATLAB, implement the differential equations that describe the evolution with time of along-track , cross-track and vertical position. (Inertial Navigation System). and 2) for a...

If most of the mass/energy of a proton is due to the kinetic energy of its quarks and gluons, rather than interaction with the Higgs field, then how can we explain its inertial mass, i.e. its resistance to acceleration, as being due to a drag induced by the Higgs field? Alternatively imagine...

Hello there! According to quantum physics, do the electrons have inertial mass? I read somewhere electrons were an amount of energy, with no mass at all. I think I'm confused about the concept of "mass" since I know two, the one they taught me at school, which I'm considering as inertial mass...

Post any thoughts or ideas here.

One can use the Principle of Extremal Aging to calculate the path of a freely moving body (in an inertial frame not subject to any forces) in spacetime, curved or flat. Why extremal? Why not just maximal? All the examples I know of involve maximum proper time for a freely moving body. For...

I wanted to understand something about Inertial frames especially as they are talked about in SR. It appears that the laws of physics should hold the same in them. Now I understand that inertial frames only involve things moving relative to each other and moving in constant speed so you can...

Can anyone please explain schuler cycle, please don not start explaining with same old pendulum with the length of radius of Earth stuff. why is it required ? what is that all about ?

I'm trying to learn what is the difference between the inertial and gravitational mass. According to: http://www.physlink.com/education/askexperts/ae305.cfm and https://www.physicsforums.com/showthread.php?t=147282 there is practically no difference (as stated by the Equivalence principle)...

In classical mechanics, I can measure the inertial mass of a particle by measuring force and acceleration: m=F/a. In QM, this equation only holds for expectation values <F> and <a>. Does this lead to the fact that inertial mass is not an observable? Is there a deeper underlying principle which...

The first law of motion says that it takes force to accelerate something. The second law of motion says that F=ma. So now my teacher says that the first law is for inertial reference frames, while the second is for non-inertial reference frames. This really annoys me because I don't...

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...

An inertial frame is one which is not accelerating. i.e if I'm sitting in an accelerating bus or plane I'm not an inertial observer however if I am in a bus or train traveling at a constant velocity i.e zero acceleration then I am an inertial observer. One thing Id like to ask here is that...

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...

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...

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...

We have had several threads lately discussing the nature of inertia and inertial forces. Here is a practical exanmple for open discussion. Take a flexible bar and closely thread several masses onto it. Clamp both ends. Arrange a disturbance to provide a flexing of the bar. This will...

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...