Reference Definition and 1000 Threads

  1. W

    Cons. Angular Momentum & Reference Frames

    Hi! I'm currently a student taking a classical mechanics course. Finals are coming up, and I've come to realize that I seem to have a firm grasp of most of the material (energy, forces, etc...) but not momentum. I know this because I was flabbergasted by a problem on my last midterm that...
  2. Z

    Lorentz Transformations and Reference Frames Problem

    Homework Statement In the old West, a marshal riding on a train traveling 35.0 m/s sees a duel between two men standing on the Earth 55.0 m apart parallel to the train. The marshal's instruments indicate that in his reference frame the two men fire simultaneously. (a) Which of the two men, the...
  3. P

    5V to 5V precision voltage reference

    Is there any IC that can output a precision 5V from a 5V supply?
  4. J

    Calculating Drag (having circular reference problems)

    Homework Statement I don't know if it's possible but I am doing a physics EEI on drag. I know to find drag you need instantaneous velocity which can be found through (change in x/ change in t) but i cannot find displacement unless i find velocity :S.. Homework Equations d = 0.5 x p x...
  5. J

    How Do Rotating Reference Frames Affect Forces on a Merry-Go-Round?

    Looking down from a stationary tree branch, a merry-go-round spins in a counterclockwise direction with an angular velocity of 1 radian per second. a squirrel of mass 0.2 kg sits on the outer rim of the merry-go-round, at a radius of 2.0 meters. a) what is the magnitude and direction of the...
  6. P

    Precision 5V Reference: LT1085 vs LM317

    Anyone can suggest a very precise and constant 5V reference? I Google and see many are recommend LT1085 and LM317? Which one is better? Any better recommendation?
  7. J

    Inerital vs Non inertial reference frames: quick conceptual question

    Homework Statement I'm doing a problem in which an ant crawls in a circle on a spinning pottery wheel. Say I'm looking at the friction which holds the ant in place. It keeps the ant from slipping. Looking at it in the inertial frame of reference, I know that the centripetal force points...
  8. R

    A sliding puck analyzed from an inertial reference frame

    Homework Statement Located here:http://imgur.com/qP9fd.png" The Attempt at a Solution I don't know how to do this problem. First of all how do I approach it? Should I do a free-body diagram? Should it be done at position 1? How do I account for the different frame of reference...
  9. K

    Pendulum tension in rotating reference frame

    Homework Statement A student is in a rotating chair with a pendulum hanging down in the middle of the rotation. . I need to calculate the difference in tension when the bob is hanging vertically and when the chair is rotating. The length of the bob and string is 65.3 cm. The radius of the...
  10. J

    Reference that explains general relativity

    Hi guys, I need to write few paragraphs to explain Einstein's formulation of gravity in terms of the metric, christofell symbols, and Reimann curvature tensor. I also want to write about the veirbein and spin connection formalism of gravity. Can anyone suggest good, yet simple references...
  11. A

    Why is the speed of light same in all reference frames?

    kindly be descriptive
  12. A

    Events in different reference frames

    I am having trouble with measuring coordinate time in different inertial reference frames. For example: Say a car is driving around a circular track (at constant v) and passes a stationary observer. I'll call this event A. Then the car makes another lap and passes the observer again (Event...
  13. H

    Electrostatics and reference frame

    Hi, I'm stuck with a question concerning electric fields : Can an electrostatic potential drop exist in (what I would call) a 0 dimensional system ? Let's imagine we are in a region of space where there is nothing but a uniform magnetic field. So the problem is anisotropic but does not...
  14. J

    Major difference of Inertial and non-inertial frame of reference ?

    Major difference of Inertial and non-inertial frame of reference ?? What is the major difference or differences of Inertial and non-Inertial frame of reference?? Is it only: Inertial - Constant velocity, obeys the law of inertia Non-inertial - Acceleration, disobeys the law of inertia
  15. P

    Physics Reference Handbook: A Comprehensive Guide for All Levels of Study

    Hy! Might someone recommend a good physics reference handbook. It seem there's plenty of mathemathical ones around, but when it comes to physics, there are only books for certain areas. I've just started my 1. year of physics, and would laike to have a reference manual which i could use...
  16. 1

    Light's constant speed and frames of reference

    Been reading up on physics out of pure interest, just learning really. Mainly started special relativity and learning about the inertial frames of reference. I think I understand that, but here's what I don't get. If from one inertial frame of reference moving at a constant 100 MPH, I toss...
  17. M

    How to use results from different classes into one class by reference?

    Homework Statement I have: - 1 class to read a data series (see text file attached) (series.h and series.cpp) - 1 class for a function (function.h and function.cpp) I'm trying to create another class which has input from 2 above class (as constant references) and produce output which has...
  18. J

    Rotating Frames of Reference question.

    Homework Statement You are standing on a slowly rotating merry-go-round, turning counterclockwise as viewed from above. You are holding a string from which is suspended a rubber stopper of mass 45g. You are 2.9m from the center of the merry-go-round. You take 4.1s to complete one revolution...
  19. E

    Which reference should I choose for my DoD scholarship/internship application?

    Hey all, I'm applying for an scholarship/internship with the DoD at an air force facility. I have to submit two reference letters. One will be acadamic and I have that figured out. The second will be from one of two supervisors at my workplace where I am currently a co-op. The logical choice...
  20. J

    Different frames of reference and particle production? a contradiction maybe?

    Hi, Second time I'm writing this question, the first one seems to have been lost in cyberspace but sorry if it somehow comes back and appears twice. Anyway, you know how kinetic energy depends on velocity, so that the energy of a particle collision will be different for two frames of...
  21. B

    Problem in inertial reference frame

    Well, in principle, this problem seems very easy but I don't know the exact explanation.Here we go. We have a truck and a pack in its back.The bed of the truck is frictionless and the pack is stopped by a small piece of wood of something like that. The size of the pack is whatever(for...
  22. L

    Simple question about inertial frames of reference

    Hello, I know that this is going to sound stupid, so please forgive me, but could someone give me a brief and simple definition of what an inertial frame of reference is and what a non-inertial frame of reference is? Thanks, Louis
  23. D

    Reference suggestions for a struggling chemist.

    Hello All, Can anyone suggest some good references or books that can help me get used to working problems with the Dirac notation and the mathematics of Hilbert Space? I'm a new Ph.D. student in chemical physics, and I did my undergrad in Chem, with a math minor. I'm now taking graduate qm from...
  24. bcrowell

    Defining a manifold without reference to the reals

    Most definitions I've seen for a manifold are based on the idea that small neighborhoods are homeomorphic to \mathbb{R}^n. To me this feels a little like defining a bicycle as a car that's missing the engine and both the wheels on one side. The real number system is this big, sophisticated piece...
  25. Y

    Absolute motion's point of reference

    According to special relativity acceleration is an absolute motion, so according to what is it moving?
  26. K

    Find drag given reference area and speed

    Homework Statement What is the drag force on a 1.6 m wide, 1.4 m high car traveling at 30 m/s (approx 65 mph)? Homework Equations drag force=.5*p*v^2*coefficient of drag*A The Attempt at a Solution density of air depends on temp but that's not given so I used a density of 1.2...
  27. W

    Particle energy and momentum in different reference frames

    Homework Statement A particle is observed in a certain reference frame (i.e. observer A) has a total energy of 5GeV and a momentum of 3GeV/c. (a) What is the energy of the frame in which its momentum is equal to 4GeV/c. Homework Equations E'={\gamma}E-{\gamma}{\beta}(cp)...
  28. S

    Frame of Reference: Does Stuff in the Frame Matter?

    Okay, weird question. Sorry if this is really stupid but it's been bugging at me for days now. First, let me lay out my current assumptions/understanding of what's going on. The current theory seems to be (to an amateur like myself) that there is no fixed space-time. That to talk about...
  29. G

    Electromagnetism in Reference Frames

    If observer A was at rest with respect to a charge that was moving with a constant velocity |v| > 0 in observer B's reference frame, would observer A detect a magnetic field?
  30. Jonnyb42

    Speed of light in Non-Inertial reference frame?

    I see a lot of places, "The speed of light is the same in all inertial reference frames." But is it the same in non-inertial reference frames too? For example, your reference frame/observer is accelerating according to someone else holding a flash light, at the moment they meet, the other...
  31. A

    Reference Frames in Simultaneity

    Lets say that a person in a moving train throws a ball in the direction of motion from one end and hits the other end of the train at 10 mph (relative to the person on the train). According to special relativity, from the perspective of a platform observer though they would see the ball having...
  32. J

    Quick Reference Frames Problem. Soon

    A ferry cross a river of width d. The speed of the boat is v relative to the water, and the speed of the tidal current is w parallel to the riverbanks. The ferry landing points are directly opposite each other on each side of the river. How long does the shortest return trip take? My attempt...
  33. A

    Why does Newtonian mechanics include relative motion between inertial frames?

    I know that in Newtonian mechanics an inertial frame of reference moves relative to absolute space. But why does Newtonian mechanics include the contention that two inertial reference frames move relative to each other? It seems that if you have an absolute reference frame then there is no...
  34. M

    Help with frame and reference problem

    You are on an airplane traveling due east at 100 m/s with respect to the air. The air is moving with a speed 35 m/s with respect to the ground at an angle of 30° west of due north. What is the speed of the plane with respect to the ground? __________ So here's what I am doing: Drew the...
  35. P

    Reference book for gravitational force

    hi, please anybody tell reference book for gravitational force, quantum gravity, black holes.
  36. O

    Do Laser Beams from Spacecrafts Travel at Different Speeds?

    Hey guys I don't think i have the correct solution to this question. I would say tht the laser beams would bothe reach the planet at the same time, but this just seems way too easy. Any hints/thoughts/suggestions on solutions to this question? Thanks Two spacecraft are flying towards a...
  37. P

    Hi,please anybody tell any reference book for astrophysics.

    hi, please anybody tell any reference book for astrophysics. i am interested to study celestial body and black hole. where it is available ?
  38. S

    Is there preferred reference frame for motion in the universe.

    For a long time, I have wondered if space has a preferred reference frame. As one looks at the cosmic microwave background radiation, ask your self what would it look like if I accelerated myself in one direction. You would expect a bluer shift in one direction and redder shift in the other...
  39. P

    Relativity, reference frames and Lorentz transformations

    Homework Statement The system S' moves in relation to the system S with velocity \upsilon along the -x- axis. At the time when the beginnings of the coordinate system are in the same point, clocks in both system shows t=t'=0. Which coordinates will have a reference point during the motion in...
  40. A

    How does the energy and time dilation of objects moving at high speeds work?

    Assume you have two objects, with nothing else, moving directly away from one another, each at 51% of the speed of light. But, from the frame of reference of one object, the other is going 102% of c, an impossibility. How does this work? And: Those same two objects, which has more energy...
  41. atomqwerty

    A question about reference system and time dilation

    Hi everyone, These days I've been reading about relativity (special) in a book of general physics, and I have a doubt about the reference system: If I stay on Earth and I observe a rocket traveling away from the Earth with a great velocity (let's be 0.5c), and I notice that time inside the...
  42. E

    Inertial reference frames problem

    Homework Statement An example of an inertial reference frame is: A. any reference frame that is not accelerating B. a frame attached to a particle on which there are no forces C. any reference frame that is at rest D. a reference frame attached to the center of the universe E. a reference...
  43. DaTario

    Experimentally probing the photon's reference frame

    Hi All, Suppose a photon is approaching the origin of set of three cartesian axes, along the negative part of the z axis. If we put a slit, geometrically defined as: 1a) half plane z = 0 and x >= epsilon 2a) half plane z = 0 and x <= -1 * epsilon Note that the slit width is 2 *...
  44. B

    Newtons first law and inertial reference systems. (noob)

    Hi everyone, Recently i started a self-study in classical physics by reading through some books. In the section that described Newton's first law I stumbled upon something that did not make much sense. The following section of text got me confused. "If the net force acting on a body is...
  45. F

    LaTeX Latex Homework Ref: Get Help in Forums

    Homework Statement Can someone point me to a reference for Latex that can be used here in the forums? Thanks.Homework Equations The Attempt at a Solution
  46. D

    De Broglie wavelength and it's dependence of the frame of reference

    Hello, I've always wondered about the "relativity" of the De Broglie wavelength. The wavelength depends on the momentum of the specific thing we are observing, thus on different frames of reference(F.O.R from now on :P) we might get different answers. I have been looking through the web to...
  47. W

    Any good reference on construction of irreducible representations of SU(N)?

    how to construct an irreducible representation of SU(3)?
  48. M

    Rotating reference system - centrifugal force

    Hi! Can someone explain this expression for the centrifugal force? F = -mw x w x r, where the underline refers to vectors. (sorry for notation) w is the angular veolcity, m mass, a r is the radial vector. I can't really see where the expression comes from. Can you indentify and...
  49. E

    Need reference for material properties

    I am an electrical engineer and not familiar with this. I need to look up the permittivity and conductivity, density and acoustic speed of some common fluids: sea water, de-ionized water, castor oil, alchohol, ... Where would I find some reference containing these numbers? Thank you.
  50. F

    Kinetic energy, heat, and reference frame

    I'm having some trouble reconciling the following facts: 1) that kinetic energy depends on v _squared_, 2) at the same time energy is conserved in all reference frames, and 3) reference frames transform linearly in v in classical mechanics (galileo transform). I've basically been able to boil...
Back
Top