Inertial Definition and 500 Threads

Suppose a person A is standing in a bus and bus is accelerating forward then when a person B standing outside observes A he see that A is accelerating in forward direction then there must be a force acting on him which is making him accelarating(because Newtons first law holds in Earth's frame)...

Suppose a person is standing in a bus, moving with constant velocity and then driver applied the breaks and the person standing moved forward as if something pushed him from behind Whats the reason behind this Is it because bus has become a non inertial frame and we have to add psuedo forces to...

Consider a specific reference frame (0XYZ) attached to Earth. A point (origin) being selected, coordinates are ascribed along with a vector basis. This reference is non-inertial because it is locked to Earth and the acceleration of Earth is not zero. Suppose upon rising one morning I felt...

Let's assume that a and b charges are moving. now in our lab frame there will be a electric+magnetic force whereas in a rest frame of either of the charges, there will be only an electric force. So, two inertial observers will measure different forces?

Consider a disc being pulled by a constant force F and it is performing pure rolling. Now, the disc has a certain acceleration, point A has a acceleration in right direction and another centripetal acceleration in vertically upward direction but it has zero instantaneous velocity because of pure...

There is a video on YouTube where Sean Carroll says for Newton it was just an accident that inertial mass equals gravitational mass, but with the general theory of relativity it became obvious that it has to be so. How does one see that? My own attempt has been consisting of transforming...

I am a Rutgers and NJIT-educated professor of Physics, now under contract to Farmingdale State College and Nassau Community College, with other recent assignments at LIU Post and the BOCES Regional STEM High School. I embarked on doctoral-level studies in 2010 at Stony Brook University in their...

It is not the laws of physics, but the forms of laws of physics which are the same in all inertial frames. Comment."The forms of laws of physics are the same in all inertial frames" is a necessary condition (put by scientists ) to get satisfied by something which has to be called as a law of...

I've read about the equivalence between inertial mass and gravitational mass. But i can't undestand why is gravity more special then other kinds of force. I mean, why isn't charge equivalent to inertial mass? After all charge plays the same kind of role of gravitational mass in another context.

Hello everyone, here I come with a question about inertial frames as defined in General Relativity, and how to prove that the general definition is consistent with the particular case of Special Relativity. So to contextualize, I have found that one can define inertial frames in General...

Homework Statement A particle is accelerated so it has a total energy of 10GeV measured in the accelerator’s rest frame. The particle's momentum is 8GeV/c in the same frame. Calculate... a.) Rest mass of the particle b.) Energy in an inertial frame in which its momentum is 6GeV/c c.) The speed...

Hi, I have a disk of diameter r, and the mass of the disk is 1kg. I'm going to rotate the disk at its center. my question is: 1. let's say I put a load of m kg on top of the disk, does the moment inertia of the system is as simple as (m + 1kg)r2/2? 2. does the shape of the load put on top of...

What in the mathematics of the derivation of special relativity limits the model to inertial frames? How is an inertial frame defined in the context of the derivation?

There are inertial reference frames and accelerated reference frames, and the laws of physics change depending on the frame through which you're observing them. The universe when viewed through an inertial frame won't let you go faster than light, but the very same universe when viewed through...

From Chris' perspective Bob is traveling with 1.5*108 m/s in direction a. Angelica is also traveling with 2.4*108 m/s in direction a. From Bob's perspective Chris is traveling with 1.5*108 m/s in direction b (The opposite of x). Angelica is traveling with 1.5*108 m/s in direction a. They all...

Suppose I am observing a object in a noninertial frame from a noninertial frame , then what will happen to the forces acting on a object with respect to both the frames, frame of reference (FOR) moving uniform with inertial FOR are themselves inertial frame , does it follow the same with a FOR...

Homework Statement System S' moves with constant speed v=(vx,0,0) respect to the system S. On the S' system a particle moves with a constant acceleration a=(ax,ay,az). What is the acceleration a'=(ax',ay',az') measured from the system S?. Homework Equations Lorentz transformation The Attempt...

Homework Statement At the roller rink, two 20-kg girls accelerate toward each other until they are each moving at 2.7 m/sin the Earth reference frame. They then collide stomach-to-stomach, grab on to each other, and fall to the floor. A. Calculate the magnitudes of the momentum of each girl...

Homework Statement Homework Equations Centripetal acceleration$$=\omega ^2R$$ Coriolis acceleration $$=2v_{rot}\omega $$ The Attempt at a Solution [/B] Think of the mass as lying on an incline. The forces I know are parallel to the incline are $$mgsin(\alpha), \mu N$$ Forces I know are...

Homework Statement Plane harmonic waves of 1/p, 1/q, 1/r and 1/s are travelling, respectively, in the directions of the (non-unit) vectors (1,1,1), (1,-1,-1), (-1,1,-1) and (-1,-1,1). Show that there exists an inertial coordinate system in which they have the same frequency if and only if...

Homework Statement $$g_o=\frac{GM}{R^2}e_R$$ where g0 is the gravitational acceleration, G = 6.67 * 10-11Nm2 /kg2 is the universal gravitational constant, M= 5.98 *1024 kg is the mass of the Earth, and R = 6.38 * 106 m its radius $$g = g_0-ω*[ω*(r+R)]$$....(8.29) where gravitational...

Homework Statement Two inertial frames S and S' are in standard configuration, the frame S' is moving along the x-axis of S with velocity v. In S' a straight rod parallel to the x' axis moves in the y' direction with velocity u. Show that in S the rod is inclined to the x-axis at an angle ##-...

While investigating about the curl I have found this interesting perspective: http://mathoverflow.net/a/21908/69479 I lack the knowledge to do the derivation on my own so I would like to ask for your help. I am an undergraduate. I do not understand what a "first order differential operator"...

Homework Statement Need to find the time t taken for m to reach the bottom Homework Equations F = ma The Attempt at a Solution [/B] I don't know how to go about solving this from an inertial frame. In my view, the only two forces acting on this block are mg, which has a mgsin(theta)...

I don't understand what are the causes of the Coriolis effect for objects moving with respect to Earth. For istance consider an object free falling on the Earth from an height h. Its tangential velocity its greater than the velocity of an object on the surface of Earth, hence it moves eastward...

In the middle of the below paragraph: "only if the shift vector ##R## is along one of the principal axes relative to the center of mass will the difference tensor be diagonal in that system." I suppose the difference tensor means new inertial tensor ##-## old inertial tensor. That means the new...

Homework Statement Classical Mechanics: John Taylor[/B] (1.27) The hallmark of an inertial reference frame is that any object which is subject to a zero net force will travel in a straight line at a constant speed. To illustrate this, consider the following experiment: I am standing on the...

Hello, I am studying on my own from Weinberg's Gravitation and Cosmology and I cannot understand how he derives a solution (pg. 72). I did not know where else to post this thread since it is not homework exercise. He takes a coordinate system ## \xi^a## "in which the equation of motion of a...

Studying the acceleration expressed in polar coordinates I came up with this doubt: is this frame to be considered inertial or non inertial? (\ddot r - r\dot{\varphi}^2)\hat{\mathbf r} + (2\dot r \dot\varphi+r\ddot{\varphi}) \hat{\boldsymbol{\varphi}} (1) I do not understand what is the...

Special relativity is one of the most tested theories in physics. A central postulated of SR is that the speed of light is the same for all observers in inertial reference frames, and this leads to time dilation and the other effects that have been tested with a high degree of precision. We...

As described in Wikipedia as well as this entry http://physics.stackexchange.com/questions/172739/is-the-lay-explanation-of-the-equivalence-principle-wrong, "being at rest on the surface of the Earth is equivalent to being inside a spaceship (far from any sources of gravity) that is being...

And a cartesian axis system in physics? I thought about that and my answer is that a cartesian axis system is the same as a inertial frame of reference, is that true?

inertial frame is one in which isolated particle has constant velocity but is there actually any "isolated particle " ? how then can frame be defined as or not being inertial ? or is it that - for a system in which acceleration due to external forces is equal for all members , the frame of...

Suppose we have an equation in inertial frame A. \begin{equation}\frac{{}^Ad\bf{H}_C}{dt} = \bf{M}_C\end{equation} Now we want to switch to body fixed frame B. For this need to employ correction factor {}^A\bf\omega^B\times\bf{H}_B. Why do we have this correction factor? How to derive this...

Hi! I am having a little trouble with a question asked by a colleague. There’s a ball B with a certain mass M, at rest. A small ball A of mass m is moving with speed v toward M. If m=M, and the collision is perfectly elastic and the two objects perfectly rigid, than we know that A would come...

Thinking and reading about the twin paradox recently, I encounter a lot of explanations and resolutions that don't make sense to me. At its most basic, the issue is- when two bodies are in different frames of reference, why shouldn't relativistic effects affect both equally, negating time...

I'd like to know if the diagonal of a rectangular thin foil is an inertial principal axis.I know that if an axis isn't a symmetry axis then it isn't a principal axis. In the rectangle the diagonal isn't a symmetry axis, so it shouldn't be a principal axis. Is it correct? So, if I consider that...

Homework Statement A platform rotates with ##\omega=10## rad/s around ##z##-axes. A ball is connected, with a yarn to ##z##. Its distance to the axes is 15 cm and it rotates with ##\omega=10## rad/s. There isn't friction between platform and ball. Suddenly, the angular velocity of the...

I know that this question has been asked many times before on this forum, but on every existing thread either the question or the answers, or both, were too vague. I understand that inertial mass is defined as the property of an object to resist change of its velocity, that is the mass that...

When rotation exists, so does the radial acceleration. It can be defined as ar=-ω2xr So there is a kind of acceleration with rotation all the time. Thus, we have to use non-inertial reference frame all the time. Could a rotational movement be analysed in an inertial ref. frame?

Homework Statement an object is sliding on an elliptical hill shown in picture. what is the direction of (inertial) centrifugal force at each moment? Homework Equations F=mv^2/r The Attempt at a Solution I think it should be towards the center of ellipse and value of r in the formula varies...

I mean, a body with higher temperature has higher energy so is it heavier than before? We know from e=m*c^2 that energy is equivalent to mass

Hello, in general relativity we introduce local inertial frames to be such frames where the laws of special relativity holds. Let ξα the coordinates in the local inertial frame, so we get ds²=ηαβdξαdξβ. If we switch the frame of reference to coordinates xμ : ξα=ξα(x0,x1,x2,x3) and with...

I wanted to check my understanding of momentarily co-moving inertial frames, so I came up with this example: Consider an inertial frame (with unprimed coordinates), about whose origin a clock moves in a circular path with constant speed, ## v ##. What is the time elapsed on the moving clock...

I'm 11 and I'm trying understand what Special Relativity is about. How many different inertial frames of reference do we have and what are they?? I know what it means.

Homework Statement Hello, I have an exam later in the week and I'm trying to understand how to this problem. Homework Equations Sum of forces. Sum of moments. The Attempt at a Solution I broke the mechanism into 3 pieces, the crank, connecting rod, and slider and then began to analyze...

I have done a search online to understand how to convert ECI to ECEF. I wanted to learn what the conversion is so I could just create a MATLAB script to make it happen. My problem is that most of the information I find assumes you already have some knowledge about ECI and ECEF. If I had more...

Imagine two observers, one accelerating and one inertial. The accelerating observer detects a thermal bath whereas the inertial observer detects a vacuum. I would imagine that this hot gas would thermalize the accelerating observers spaceship, but how does the inertial observer reconcile this...

Claim: The acceleration (both direction and magnitude) for any object is the same in any inertial reference frame. Is this claim true? I think it is, but someone mentioned to me that time may be an issue as it's not agreed upon in all inertial reference frames. I'd appreciate any references...

This might have been answered before but it's something that has been bothering me. A rocket in space will move in a straight line. If I apply thrust, it still moves in a straight line unless I apply the thrust in a different direction. So unless I have rocket nozzles attached to the side...