Reference Definition and 1000 Threads

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...

i'm not sure if this is the place to ask this, so let me know if I'm in the wrong section. I'm starting a class tomorrow where we're going to be researching how different components of a satellite work. our professor wants us to know what we learned in Electromagnetism and Waves, primarily...

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...

Homework Statement I'm doing some preliminary research for a potential IB extended essay topic. It involves thermal stresses in fused glass; details aren't that important right now. But I need to find a table, equation, or SOME sort of reference that gives me the relationship between the...

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...

Homework Statement A smooth level table is centered on a platform which rotates. - The uniform rotation is at: one revolution in 12 seconds - Two perpendicular lines are drawn through the centre of the table, intersecting a circle of 1.20m radius at points: A', C', B' & D'. - Two men, H'...

I have a very basic question about Special Relativity. I am very limited on my knowledge of physics and math and even more so on SR so please keep that in mind when answering. I have read the basic example many times of two spaceships traveling towards each other with a constant velocity. The...

Which of the following statements are true? 1. The index of refraction is the ratio of the vacuum speed of light to the speed inside the medium. 2. The index of refraction is independent of the wavelength of the light. 3. If a light beam is incident perpendicular to the surface of another...

I have a question about zero reference. Let us assume the expansion of the universe is due to the expansion of space-time. The analogy I have heard is sort of an expanding foam to account for the faster expansion of the perimeter. Here is the question, if we assume our Earth reference, within...

Can someone help clarify this equation from classical dynamics? It doesn't seem to make sense. Here's my textbook's explanation. A particle has position vector \vec{r} in a non-rotating, inertial reference frame (the 'un-prime' frame). Suppose we want to observe the motion of this object in...

Hi, I'm a grad student in computer engineering and my research involves a fair amount of mechanics (forward/inverse dynamics). I'm working with rigid multibody systems with many DOFs (40 to 50) representing human characters. I've come across this...

Homework Statement here: http://img144.imageshack.us/img144/7518/26700576ok1.gif Homework Equations The Attempt at a Solution well, I tried to solve the motion equation from the inside table. I think there should be a d'elambertian force to the left, and friction force to the...

A car travels due east with a speed of 35.0 km/h. Raindrops are falling at a constant speed vertically with respect to the Earth. The traces of the rain on the side windows of the car make an angle of 65.0° with the vertical. Find the velocity of the rain with respect to the following reference...

It occurred to me that, as far as calculating the position or movement of objects a reference frame can be rotational, see the http://en.wikipedia.org/wiki/Rotating_reference_frame" . So instead of seeing the Earth as orbiting the sun you could say that the Earth is stationary and the rest of...

Hi All, I'm a bit confused about the definition of an internal reference system! I know that a system can be considered inertial if there is no acceleration relative to the background stars. In other words, a system moving at constant velocity. What about the rotation of such a system...

Homework Statement particle moves in a xy plane, force F is actiong on it, proove that there exists a frame rotating with angular velozity w.z in which the equations of motion of this particle will be x''=2wy' y''=2wx' Homework Equations m-mass xy-plane in which object moves F=-kr k=constant...

Dear all, I am working on a thesis right now and looking for the reference data regarding to the pressure distribution on this kind of pod (or similar structure) under the fuselage. Is there any people can give me some hints to find those data? Thanks a lot~...

I am wondering about the generality of reference frames, and how abstract they can be. Is it possible for a vector in one reference frame to not exist in another frame? Or is there always a relation between two reference frames? Also, are two reference frames like two different sets of...

Is there a Latex reference for new users? I was unable to figure out how to post an infinite integral with which I need help. I got the integral sign to post and also the upper boundary but could not get the integrand or lower boundary to appear correctly. thanks

According to Einstein's relativity theories, each observer is afforded a frame of reference which can be considered central and stationary. What would the universe look like to the frame of reference associated with a photon observer. Would all things be moving past the photon at the velocity...

I don't know the answer to this question but it may only require common sense: Let's say an apple on the surface of the Earth weighs 0.25 Kg. Imagine the apple as the little Earth and the whole Earth on top of it. What is the weight of the Earth with reference to that apple? I suspect...