Equivalence Definition and 721 Threads

  1. D

    Matrix Row Equivalence: Understanding Non-Singular Matrices"

    Every matrix is row equivalent to a unique matrix in echelon form? False, a matrix is row equivalent if it is non-singular. Is the above correct reasoning for the initial statement.
  2. D

    Proving Equivalence Relations for Real Numbers x, y, z in R

    x,y,z\in\mathbb{R} x\sim y iff. x-y\in\mathbb{Q} Prove this is an equivalence relation. Reflexive: a\sim a a-a=0; however, does 0\in\mathbb{Q}? I was under the impression 0\notin\mathbb{Q} Symmetric: a\sim b, then b\sim a Since a,b\sim\mathbb{Q}, then a and b can expressed as...
  3. J

    Boolean Equation Equivalence Problem

    Homework Statement Part a was to prove the equivalence of the two equations using a truth table. Done. Part b is to prove the equation using the 10 properties of boolean logic, as seen in http://en.wikipedia.org/wiki/Boolean_logic#Properties" We are trying to prove: (p∨q)∧(¬q∨r) ⇔...
  4. H

    Testing the Equivalence Principle with Spectral Anisotropies

    It suddenly occurred to me that I've never heard of a test of the Equivalence Principle itself - such as something like ... An accelerating laboratory [in space] can see very obvious effects in external astronomical observations. Depending on the rate of acceleration, there would be...
  5. jaketodd

    Equivalent Trajectories in Relativity: Observer Effects

    In relativity, can two sets of trajectories, carried out at different times, be considered equivalent if they only differ by when they change directions as they traverse their sets of trajectories? They traverse the same trajectories. The only difference is the rate at which they traverse the...
  6. X

    Equivalence of mass, energy and gravity

    Hi guys, I'd like to hear what you think about a little thing I did talking about the equivalence of mass, energy and gravity. I used planet Earth as an example. Here's the link to the .docx Word file: http://www.angelfire.com/bug/chaos1/Gravity_Rotation.docx" My premise is that the more...
  7. N

    Proving Numerical Equivalence of Real Number Intervals with S-B Theorem

    Homework Statement Using the Schroeder-Bernstein Theorem, prove that any two intervals of real numbers are numerically equivalent. Homework Equations Schroeder-Bernstein Theorem: Let A and B be sets, and suppose that there are injections from A into B and B into A. Then, there exists a...
  8. F

    Linear Algebra: Equivalence of Linear Transformations

    Homework Statement 1) two linear transformations B and C are equivalent iff there exist invertible linear transformations P and Q such that PB=CQ 2) if A and B are equivalent then so are A' and B' in dual space 3) Do there exist linear transformations A and B such that A and B are equivalent...
  9. H

    Deriving the Schwarzschild metric just by using the equivalence principle

    I've read a few papers about derivation of the Schwarzschild metric by using the equivalence principle ( http://cdsweb.cern.ch/record/1000100/files/0611104.pdf" )... but I couldn't understand them completely they assume , According to Einstein’s equivalence principle, that the influence of...
  10. D

    Smallest Equivalence Relation on Real Numbers: Proving with Line y-x=1

    1) Recall that an equivalence relation S on set R ( R being the reals) is a subset of R x R such that (a) For every x belonging to R (x,x) belongs to S (b) If (x,y) belongs to S, then (y,x) belongs to S (c) If (x,y) belongs to S and (y,z) belongs to S then (x,z) belongs to S What is the...
  11. P

    What is the volume of base added at second equivalence point?

    Homework Statement You have a solution that is buffered at pH =2.0 using H3PO4 and H2PO−4 (pKa1 = 2.12; pKa2 = 7.21; pKa3 = 12.68). You decide to titrate this buffer with a strong base. 15.0 mL are needed to reach the first equivalence point. What is the total volume of base that will have...
  12. D

    Equivalence Relation in Math: Proving Transitivity

    \forall a,b\in \mathbb{Z} a\sim b iff. \left\vert a-b \right\vert \leq 3 I have already shown reflexive and symmetric but not sure on how to show transitive. I know the definition.
  13. I

    Why is the Equivalence Principle True?

    The equivalence principle states that an accelerating observer who has no external information (view of fixed stars, etc) can in principle not perform an experiment to determine whether he is either undergoing linear acceleration or at rest in a gravitational field. This leads to the equivalence...
  14. N

    Three Questions About Energy-Mass Equivalence

    I read somewhere that Einstein found out in 1905 that as an object approached the speed of light (c), the object's mass would increase. He also found out that as the object goes faster and approaches "c", it also gets heavier. In fact, at "c" itself, an object's mass and energy should both be...
  15. JK423

    Is Negative Total Energy Possible in Mass-Energy Equivalence?

    Suppose you have two particles of mass 'm'. Their combined rest energy will be: E_rest=2mc^2 Its said that when they interact (gravitationaly), they're total energy will decrease due to the negative gravitational potential energy. The rest of the energy is stored in the field (they say)...
  16. M

    Describing Equivalence Classes

    Hey guys! So I am having trouble understanding equivalence classes. How are they determined?? Anyways here is my problem! Homework Statement Let A and B be two sets, and f: A-->B a mapping. A relation on A is defined by: x~y iff f(x) = f(y) a) Show ~ is an equivalence relation b)...
  17. K

    Understanding Equivalence Relations in Real Numbers and Vector Spaces

    Homework Statement I have got myself very confused about equivalence relations. I have to determine whether certain relations R are equivalence relations (and if they are describe the partition into equivalence classes, but I'll worry about that once I understand the first part). Here are...
  18. S

    Is RxS an Equivalence Relation on ExF?

    Homework Statement I need a little help in understand this question: Let E and F be two sets, R a binary relation on the set E and S a binary relation on the set F. We define a binary relation, denoted RxS, on the set ExF in the following way ("coordinate- wise"): (a,b) (RxS) (c,d) <-->...
  19. G

    Mass Energy Equivalence and Kinetic Energy

    If a particle is moving through free space (no forces acting upon it) should its kinetic energy equal its mass energy equivalence or am I getting confused. In other words is an object's kinetic energy absorbed within its mass? Is the following true? E_{kinetic} = \frac{p^{2}}{2m} = mc^{2}...
  20. N

    Proving ~ is an Equivalence Relation of A

    Homework Statement Consider the set A={(u,v,w) in R^3 : u^2+v^2>0} and define a relation ~ on A by (u,v,w)~(u',v',w') IFF there exists a "k" in R, where k doesn't equal 0: (u',v',w')=(ku,kv,kw) Prove that ~ is an equivalence relation of A Homework Equations I honestly don't know...
  21. L

    Linear Algebra Vector Spaces: Prove equivalence

    Homework Statement Prove that the following are equivalent: 1. N(A)=0 2. A is nonsingular 3. Ax=b has a unique solution for each b that exists in R^n. Homework Equations The Attempt at a Solution I think you prove this by showing that 1 implies 2, 2 implies 3, & 3 implies 1...
  22. Rasalhague

    Equivalence of mass and energy

    Some naive questions about the meaning of this expression. In what follows, I'll use the word mass for "rest mass", the magnitude of the energy-momentum 4-vector. (Answers in terms of "relativistic mass" are fine, just let me know what definitions you're using. Taylor & Wheeler in Spacetime...
  23. C

    Is the equivalence principle good for anything?

    I heard that there is now consensus in literature that a charged particle will take a DIFFERENT path around a neutral object than an uncharged particle. The reason is that the charged particle will radiate. I have even heard physicists try to wave this away as "well a charged particle needs...
  24. R

    Equivalence relations and equivalence classes

    Hey! Hoping you guys could help me with a small issue. No matter how hard I try, I don't seem to fully understand the notion of an equivalence relation, and henceforth an equivalence class. What I do understand that, in order to have and equivalence relation, it is defined to satisfy three...
  25. L

    Equivalence Relation Homework: Is R on X Reflexive, Transitive, Symmetric?

    Homework Statement Let X be Z*Z, i.e. X is the set of all ordered pairs of the form (x; y) with (x, y) are integers. De fine the relation R on X as follows: (x1^2, x2^2)R(y1^2, y2^2) = (x1^2 + x2^2) = (y1^2 + y2^2) Homework Equations By definition, an equivalence relation bears the...
  26. P

    Equivalence Relation: Proving R and Finding Class

    [SIZE="2"]Moderators note: thread moved to homework area. Please note, homework assignments or textbook style exercises for which you are seeking assistance are to be posted in the appropriate forum in our https://www.physicsforums.com/forumdisplay.php?f=152" area. This should be done whether...
  27. P

    What is Numerical Equivalence of Sets and How is it Defined?

    1. Define numerical equivalence of sets 2. I'm not sure how in depth the definition needs to be, how is my current def? 3. X is numerically equivalent to Y if \existsF:X\rightarrowY that is bijective or there are two injective functions f:X\rightarrowY and g:Y\rightarrowX
  28. N

    Is R an Equivalence Relation in R x R Based on a Quadratic Equation?

    In R x R , ley (x,y) [FONT="Palatino Linotype"]R (u,v) if ax^2 +by^2=au^2 + bv^2, where a,b >0. Determine the relation [FONT="Palatino Linotype"]R is an equivalnce relation. Prove or give a counter example
  29. P

    Equivalence Classes of Continuous Functions with a Common Value at x=4

    Homework Statement Identity if it is an equivalence relationship and describe the equivalence class. The relationship T on the set of continuous functions mapping R to R, where fTg iff f(4)=g(4) Homework Equations The Attempt at a Solution It is an equivalence relationship just...
  30. N

    Quantification logic and equivalence relations

    I wasn't sure whether to post this in the algebra forum or here, but it seems that this is more of a logic question so I'm going with here. I am trying to understand whether there is a difference between the following two definitions of an equivalence relation: Definition 1: A binary relation...
  31. G

    Weight, Acceleration, Gravitational Equivalence

    When you are in a box it is difficult to know the difference between if the box is accelerating in space or you are standing in the box on the surface of a planet. That is correct is it not? In both the accelerating box and on the surface of the planet you can weigh yourself and if the gravity...
  32. N

    Simplifying a logical equivalence statement without a truth table

    Homework Statement [(p->r) ^ (q->r)] -> (p ^ q) -> r Homework Equations anything but a truth table! laws such as (p->q)= ~(p^~q) or (p->q)=(~q->~p) might help
  33. W

    Discrete Math - equivalence laws

    I need to show that P<->Q is logically equivalent to ( P ^ Q ) v ( ~P ^ ~Q) So far I have P <-> Q is equivalent to ( ~P v Q ) ^ ( ~Q v P ) by a example I have no idea where to go from here
  34. M

    Proving an equivalence relation

    Homework Statement On the set of integers, define the relation R by: aRb if ab>=0. Is R an equivalence relation? Homework Equations The Attempt at a Solution R is an equivalence relation if it satisfies: 1) R is reflexive Show that for all a∈Z, aRa. Let a∈Z. Then if a is...
  35. E

    An equivalence? An equivalence??

    An equivalence?? The two statements : 1)A sequence diverges to infinity . 2)The sequence is unbounded from above. Are equivalent?? If yes how do we prove it? If no give a counter example
  36. E

    Quantum physics and equivalence principle

    I read some articles, where equivalence principle is no more valid in quantum area. One example are neutrinos, changing colours (electron, muon, tauon neutrino). But formulae are not derived from fundaments, so I do not understand, where it is the catch. I read also about COW experiment...
  37. G

    Equivalence Principle: Mass Increase With Time?

    An uncharged, isolated particle of mass m is subjected to a constant force that increases its speed relative to an IRF. Its mass presumably increases as long as the force acts. Does the mass of an identical particle, held at rest in a gravitational field also increase with the passage of time...
  38. M

    Are SI Units Equivalent in Differential Equations?

    Hi all, I would like to know if any of you know about anything the equivalence of SI units for differential equations? For example, for the equation E=mc2 SI units for RHS must equal LHS. I am wondering if this would apply to differential equations? I recently came across a journal paper with...
  39. S

    Deriving Bessel Function Equation with Basic Relation

    Homework Statement Known formula:J_0(k\sqrt{\rho^2+\rho'^2-\rho\rho'\cos\phi})=\sum e^{im\phi}J_m(k\rho)J_m(k\rho') I can't derive to next equation which is e^{ik\rho\cos\phi}=\sum i^me^{im\phi}J_m(k\rho) Homework Equations Can anyone help me? Thanks a lot! The Attempt at a Solution
  40. P

    Equivalence Classes Homework: (a) & (b)

    Homework Statement \forall (a,b), (c,d) \in (Z^2), (a,b)D(c,d) \leftrightarrow a\equiv c\mod\2\and\b\equiv d mod 3 *edit* Sorry the b = d mod 3 is all part of the same line. (a) List four elements of the equivalence class [{5,3}] (b) How many equivalence classes of D are there in total...
  41. T

    Weak and strong equivalence- what is the difference really?

    Hi! My lecture notes make me really confused as to what is the difference between weak and strong equivalence. I also read about it on wikipedia, but I'm still not sure. Can anyone give an example how in real life (thought experiment?) of what weak and strong equivalence is.
  42. S

    Closed set equivalence theorem

    Homework Statement Hi guys, this problem gave me some trouble before, but I'd like to know if I have it worked out now... "If S = S\cupBdyS, then S is closed (S_{compliment} is open) Homework Equations S is equal to it's closure. The Attempt at a Solution 1. Pick a point p in...
  43. P

    Determine if the following is an equivalence relation

    Homework Statement Determined if the following is an equivalence relation, if so describe the equivalence class. The relationship C on a group G, where aCb iff ab=ba Homework Equations The Attempt at a Solution So i know there's 3 things to check: reflexive condition, symmetric...
  44. S

    Einstein's box of phonons and energy-mass equivalence

    If Einstein's box (http://galileo.phys.virginia.edu/classes/252/mass_and_energy.html ) is full of phonons instead of photons, the momentum is Mv=E/c' and time is t=L/c' where c' is the velocity of a phonon. The result should now be E=mc'^2 rather than E=mc^2. E=mc^2 is tenable to photons...
  45. S

    Einstein's box in media and mass-energy equivalence

    Einstein proposed a very simple derivation to E=mc^2 in 1940s which is well-known as Einstein’s box and a brief introduction is in http://galileo.phys.virginia.edu/classes/252/mass_and_energy.html . If this event occurs in media instead of vacuum, the light speed should be u=c/n rather than c...
  46. A

    Titration question 2 equivalence points. Am i right?

    Titration question 2! equivalence points. Am i right? Homework Statement this is the originial question. A 0.149 g sample of a weak acid (HA) requires 16.80 mL of 0.110 M NaOH to completely reach the equivalence point. What is the Molar Mass of the acid? and i got 86.63 g/mol. I have...
  47. G

    Equivalence principle to other forces?

    Why is it that to derive general relativity you use the equivalence principle on gravity and not electromagnetism for example?
  48. A

    Equivalence Relation: Can't Understand x~x+1 on Real Numbers

    Hey I can't see how x~x+1 is an equivalence relation on the real numbers? I don't understand what the relation is. Can anyone help?
  49. M

    Interpreting equivalence classes geometrically

    Homework Statement For (x, y) and U, v) in R2, define (x,y)~(u,v) if x2+y2 = u2+v2. Prove that ~ defines an equivalence relation on R2 and interpret the equivalence classes geometrically. Homework Equations (none) The Attempt at a Solution The first part is easy. I proved...
  50. TurtleMeister

    Question about equivalence principle

    First, I would like to say that this is my first post in this forum and that my knowledge of GR is weak. So I am hoping that my question can be answered in layman terms. If I hold a 1kg object in my hand, I can easily feel it's inertia if I move it from side to side. I could also measure it's...
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