Reference Definition and 1000 Threads

Dear Friends A fleet of spaceships is given, each equipped with a differential microwave radiometer, just like COBE was, whose detectors are antipodeanly pointing (this way one should catch blue shifted radiation and the other one red shifted). Could their acquisitions be used to...

Thank you in advance! Homework Statement A 3.0-kg block is between two horizontal springs. Neither spring is trained when the block is at the position labeled x=0 m in the drawing. The block is then displaced a distance of 0.070m from the position where x=0m and is released from rest. (a) What...

F= q(v x B) B= v x q*k*d/r^2 It is a basic physics knowledge magnetic field forms around moving charge, it tell us magnetic field is zero when charge is not moving and strength of magnetic field increases as velocity increases, right? Magnetic potential vector field increases with "absolute...

Hi, I am an Electrical and computer engineer. I recently decided to start studying physics in my spare time in the futile attempt to understand the universe, or at least parts and interpretations of it. I decided to start with quantum physics, a book called "Quantum Theory" by David Bohm. It...

Homework Statement A loudspeaker diaphragm is producing a sound for 2.5 s by moving back and forth in simple harmonic motion. The angular frequency of the motion is 7.54 x 10^4 rad/s. How many times does the diaphragm move back and forth? Homework Equations angular freq. (W for...

Hi, everyone:) In my mechanics book a derivation is given for acceleration in rotating reference frames. However, there is one step I don't understand. First of all, it is derived that v=v'+\omega\times r' or \left( \frac{dr}{dt}\right) _{fixed}=\left( \frac{dr'}{dt}\right) _{rot}+\omega\times...

I keep hearing how motion only exists relative to something else. But what if there is some object in space, and it is the only object in the universe. It has some kind of propulsion system, and it activates it, goes to a certain speed, then stops accelerating. Is that object really moving, or...

Einstein wrote ... Q: What would happen inre (in regards to) time if, for any reason, a clock were to be 'independent of the state of motion of [its] body of reference'? A: _____ (?)

What is "absolute reference pressure and absolute reference temperature" I am doinf a test about compressed air flow rate. There is a parameter called absolute reference pressure and absolute reference temperature. Are they 1.01bar and 273+20K?

I would appreciate it if anyone could add good quality reference books that would benefit me. I graduated in May and I have forgotten a lot of the material especially hardware design wise and my job is a mixture of embedded design and hardware design. The embedded side I am doing fine but...

Homework Statement Is a spinning frame of reference an inertial frame of reference? Homework Equations net torque, net force = ma, equilibrium --> net force = 0, net torque = 0 I've learned that an inertial frame of reference is a frame of reference which is not accelerating. The...

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...

Hi, I am looking for a all-time reference physics book, which will cover the SAT Physics Subject Test. I want a book that will give me a general understanding of Physics(Mechanics, Electricity and Magnetism, Waves and Optics, heat and Thermodynamics, Modern Physics, etc.) Thanks for your...

If in the future humans master time travel, might it be valuable to know a Universal Reference point that is common to both the present and past coordinates in space and time. For example, say we designated a single point on Earth from which all other relativistic effects are to be measured...

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...

Homework Statement Assuming that we know the density of Earth as a function of radius, we have to derive the equation for gravity as the function of radius. Homework Equations The Attempt at a Solution lets us choose density as \rho(r). I know that within a hollow sphere there is no gravity...

Homework Statement I am a bit confused about what are inertial reference frames and what is not. The text states: "We define an inertial reference frame as a reference frame in which Newton's laws are valid... Accelerating reference frames are not inertial reference frames...

Hi, I am a bit confused about a certain aspect of Special Relativity and I am hoping someone can clear this up for me. Let's say we have an event and two observers. Observer A stands a few meters from the event, Observer B is hundreds of thousands of miles from it. Relative to the event and...

Homework Statement This isn't exactly a problem. Also, it is only the first section of the chapter on trig, and this has nothing to do with trig, per se. I think it is more of like a primer for what is to come. So, whomever reads this, please try to imagine you know nothing about sin...

i've just had this thing running through my head that I'm trying to resolve: 1. two parallel wires that conduct a current (same charge carriers) will attract one another, that is the magnetic force each wire emits due to the flowing current will induce an attractive force in the other (charge...

Now correct me if I'm wrong. Gravitational singularity is when It has a defined mass but no volume and the equation for density is d=m/v. If a black hole's mass is say 10^40 yottagrams and its a singularity so it has no volume = 0. How can it have infinite density if the equation is (10^40...

This might be a dumb question to ask, but does anyone ever worry about reference frames in QM? I'm just starting my first course and don't know much yet, but it seems like if we can consider operators to be vector fields (reference to my previous post) then we might have to worry about groups of...

I have heard the following oppinion: Whether a reference frame is inertial is completely determined by whether Newton's laws are applicable for particles moving at low (that is, nonrelativistic) speeds in that reference frame. Do you agree with it?

can someone recommend some reference books on physics which are available as ebooks?

Hi. When reducing the value of measured gravity to produce gravity anomalies, the measured gravity is reduced to it's value on the geoid (conventional interpretation). This is then compared to the value generated by the reference ellipsoid at the ellipsoid surface. I would have thought...

Can anyone recommend a good introduction to contour integrals for someone not taking complex analysis? We are doing these integrals in a physics class and I'm terribly confused. I know that I have to choose contours that "go around" my poles, but I don't understand how to do this (I can't seem...

According to Alice's frame of reference, there is a 1kg object moving through space at 1 m/s along the x coordinate. When x = 0 meters, Alice applies 1 Newton of force to the object in the positive x direction. However, Bob simultaneously applies 1 Newton of force in the opposite direction...

Homework Statement 1. A boy with a mass of 50kg jumps off a 30kg boat, causing the boat to move to the right at 2 m/sec. What did the boy jump with a velocity of? a.-1.2 m/sec b.3.3 m/sec c.1.1 m/sec d.0.2 m/sec e.-3.3 m/sec 2. A 2kg cart moving in a straight line hits a piece of...

I picture two reference frames for two different objects moving relative to each other as two coordinate spaces S and S'. My question is, say both spaces start of on top of each other (ie both objects are initially stationary) and then the objects start moving relative to each other, would the...

Homework Statement You are conducting an experiment inside a train car that may move horizontally along rail tracks. A load is hung from the ceiling on a string. The load is not swinging, and the string is observed to make a constant angle of with the horizontal. No other forces are acting on...

OK, I'm working on a question regarding IRFs, but I seem to be a little confused. Question: Observer A is on the ground and Observer B in on a train moving with uniform velocity v wrt the ground. Each observes that a particle of mass m, initially at rest wrt the train, is acted upon by a...

Homework Statement the question gives me the masses and initial velocities of two balls which collide elastically and asks me to prove that it the momentum will be conserved in both a still reference frame and a moving one. Homework Equations The Attempt at a Solution i know that...

Hello, I've come up with a simple, imaginary situation that bugs me. Could someone help resolve my confusion? Let's say that a spaceship is traveling through space, and two people- observer 1 and observer 2- are watching it. Both observers can monitor the ship's speed and the amount of fuel in...

People often have trouble visualizing how time dilation can be "mutual" in special relativity. That is, if you have two clocks moving with respect to each other, in each clock's rest frame the other clock runs slower. The following example illustrates how this can be possible without...

can anybody please clearly explain me the difference between these two frames of reference with few examples. my exames are closing up. please help me.

I'm not going lie I don't know too much about relativity, though I do understand it. I haven't even gone to college yet and from what I've read so far I'm assuming there's much more to know. Anyway, in most of Einsteins thought experiments he speaks about observations in terms of 1 frame of...

Has anyone here used this book? If you have, how would you rate it. To my surprise many programmers seem to despise Schildt's books. One is usually directed to this page to make the point. I was surprised because I found his beginner's guide on C++ quite easy to read and understand. (And...

Can we create a Universal Reference point in time, where I'm defining this as a point in time and space. Imagine an arbitrary reference point, for the sake of illustration let's say Grenich, UK in the Time museum in a display case, on a piece of paper, a single micro dot of ink is marked and...

in the definition of inertial frame- a frame in which Newtons law of inertial holds- that a body will continue in its original motion unless impelled to change by a net force my problem is that, how do we know that a force is applied without acceleartion (ie only we conclude there is a force...

Problem If you throw a ball with velocity v at a wall, it rebounds with the same speed, v. What happens if you throw it at speed v towards a wall which is traveling towards you at speed w? What is your answer in the limit in which w is much larger than v? Answer Let us work in the frame of...

i need big good reference wiht pucter forbiochemistry where can i find it

[SOLVED] Non-inertial Reference Frames Homework Statement State Newton's Second Law of motion in a non-inertial reference frame. Homework Equations In an inertial frame F=ma If S and S' are two reference frames, the same point is related by r=A(t)r'+b(t) where A is an orthogonal...

I'm not sure if either Einstein or Newton said that all frame of reference are equally valid. That from my point of view, the laws of physics is the same from your point of view. All frame reference can be put on an equal footing. I was wondering, can one consider the geocentric view that the...

Dear subscribers Re: Stability test of reference electrode One of the important properties of reference electrode is its stability during measurements or potential scan. How one can check its stability in a certain electrochemical system? One of the way is to use internal reference...

hey :) So, I'm trying to switch between from one frame of reference to another, for a rotation of a 3d object. First of all, the object is rotated, through 2 perpendicular axis. Now, I need to model that rotation in another set of predefined Euler rotations. In other words, imagine a...

Homework Statement A spacecraft with its astronaut has a total mass at rest of 10^5 kg. The astronaut is to travel to a star 10 light years away at a speed such that she only ages 1 year in her frame of reference a) the quantity 1-v/c where v is her speed with respect to Earth is? b)...

According to Einstein, there is no absolute frame of reference; no such thing as 'absolute rest'. But does not the Cosmic Background Radiation provide an absolute frame of reference? An object for which this radiation is totally isotropic is at absolute rest; I gather we move relative to it at...

Just a Sci Am reference: http://www.relativitycalculator.com/articles/multiple_universes_hugh_everett/page_98.html

Hi, I'm quite new to relativity and I'm just going through some problems from past exam papers to prepare for an upcoming subject. The following question has me a little stumped: Betty is at the origin of her frame of reference. At a certain point in time, this also corresponds to the...

How can you have an inertial reference frame in which a body can remain at rest or move with constant velocity unless you postulate the disappearance of the universe? In the Michelson Morley experiment the Earth is not moving with constant velocity, it is accelerating. So the postulates of...