What is Difference: Definition and 1000 Discussions

A finite difference is a mathematical expression of the form f (x + b) − f (x + a). If a finite difference is divided by b − a, one gets a difference quotient. The approximation of derivatives by finite differences plays a central role in finite difference methods for the numerical solution of differential equations, especially boundary value problems.
Certain recurrence relations can be written as difference equations by replacing iteration notation with finite differences.
Today, the term "finite difference" is often taken as synonymous with finite difference approximations of derivatives, especially in the context of numerical methods. Finite difference approximations are finite difference quotients in the terminology employed above.
Finite differences were introduced by Brook Taylor in 1715 and have also been studied as abstract self-standing mathematical objects in works by George Boole (1860), L. M. Milne-Thomson (1933), and Károly Jordan (1939). Finite differences trace their origins back to one of Jost Bürgi's algorithms (c. 1592) and work by others including Isaac Newton. The formal calculus of finite differences can be viewed as an alternative to the calculus of infinitesimals.

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  1. I

    Contact potential difference

    Homework Statement Hi! I'm writing my lab report on the Franck-Hertz experiment and I have trouble with the contact potential difference (inelastic collision). How do you calculate it? Homework Equations See below The Attempt at a Solution The energy differences between the maximum and...
  2. R

    Schools Difference between bursary, scholarship and fellowship

    The title itself describes my query. Also, is a fellowship more prestigious than a scholarship which in turn is more prestigious than a bursary?
  3. UMath1

    Work in moving through zero potential difference

    If I were to move a positive charge from infinity to a location between two positive charges where the net electric field is zero, the electric field would do zero work because there is no potential difference right? I am confused about why this is though. As you move the charge from infinity...
  4. Rorshach

    Difference between two harmonic motion equations

    Homework Statement Hello, folks:) I'm currently having problem with properly understanding the difference and aplications of two equations which resemble each other greatly, but the difference makes it difficult for me to tell exactly which one is for what. 2. Homework Equations Those two...
  5. D

    I Difference between Zero-Field Cooling and Field Cooling

    I am currently doing a experimental project work on superconductors. I am supposed to study properties of FeTeSe. I am having trouble understanding the difference between Zero-Field Cooling and Field Cooling. In both cases, I am measuring magnetization with varying temperature (from lower to...
  6. C

    Calculate the pressure difference between two points

    Homework Statement Need to find the pressure difference between the two water pipes. Specific gravity of water = 1000 kg/m^3, specific gravity of oil = 800 kg/m^3[/B] Homework Equations pressure = height * specific gravity * gravitational acceleration The Attempt at a Solution I think that is...
  7. smodak

    Difference Between "Engineering Math" and "Mathematical Methods"

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  8. A

    Potential Difference. across capacitors

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  9. Ssnow

    I Difference between the projective space and one its part

    Hi everybody, I want to ask if there are big differences consider algebraic objects in the projective or in the projective space with only positive coordinates? I know that the question is generic (so permit the discussion ... ). I am interested to know what happen to classical invariants if...
  10. NatFex

    B Difference between albedo and emissivity?

    This has been asked already, but it was either answered incorrectly or I'm just not understanding it right. I was under the impression that albedo is the ratio of radiation reflected off a body compared to the total incident on that body. Hence black bodies have an albedo of 0 and more...
  11. F

    Pressure Difference: Is the Solution Wrong?

    Homework Statement is the solution given wrong ? from the bernoulli's equation , (PA-PB) / ρg = hf + ZB - ZA , am i right ? P/s : the Velocity at A and B are the same , so they cancel each other ... but in the solution , the author gave (PA-PB) / ρg = hf + ZA - ZB which is 18.27 +40 , IMO , it...
  12. Z

    Engineering Graph: difference between cycle & circuit

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  13. egio

    I Difference between integral and antiderivative?

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  14. P

    Weight difference at Mt. Everest summit vs. sea level

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  15. F

    I Difference between superposition and mixed state

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  16. terryds

    Potential difference between two points on a circuit

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  17. I

    Potential Difference Between Points on Dielectric Triangle

    Homework Statement A dielectric equilateral triangle of dielectric constant 30 is inserted into uniform horizontal electric field of 100,000 N/C. What is the potential difference between two points 3 cm apart on one of the sides? Homework Equations ΔV =∫E⋅dl E' =E/κ The Attempt at a...
  18. I

    Potential Difference Across Capacitor Regions and Work Done

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  19. MullaTheMech

    Difference Between an Electron and a Positron?

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  20. J

    Difference between electric and microwave circuit?

    I understand in an electric circuit electrons in metallic materials move around by being directed by potential differences (fields!) I guess in a microwave circuit photons propagate as waves and are directed around and manipulated throughout the circuit by its geometry? Or have I got this...
  21. T

    What's the Difference Between Positive and Negative?

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  22. person_random_normal

    Incoherence of Light Sources: Phase Difference & Intensity

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  23. P

    Pulses, waves, train waves....

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  24. alexandria

    Explain the connection between Potential Difference, Current & Ohm's Law

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  25. J

    Difference between two statements

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  26. jamalkoiyess

    Programs Difference Between PhD After Bachelor & Master in Physics

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  27. S

    Difference between momentum and linear inertia

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  28. L

    A Difference between an optical and an acoustic phonon

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  29. terryds

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  30. G

    Engineering Current phase angle difference (AC circuit)

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  31. N

    Programs Difference between Phys.BS and Phys.Bs with specialization

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  32. S

    Distance from potential difference

    Homework Statement A metal sphere of radius 15 cm has a net charge of 4.2x10^-8C. At what distance from the sphere's surface has the electric potential decreased by 500V? Homework Equations V = kQ/r The Attempt at a Solution \Delta V\quad =\quad \frac { kQ }{ r } \\ \\ r\quad =\quad \frac {...
  33. P

    Difference of B-10(n,2a)H-3 cross section in ENDF/B

    In the research,it is found there is significant difference of B-10(n,2a)H-3 reaction cross section between ENDF/B-V and ENDF/B-VI (http://www.nndc.bnl.gov/).The cross section in ENDF/B-V is 10 times less than ENDF/B-VI when neutron energy...
  34. Mr Davis 97

    Programs BA or BS in Physics: Why Does Berkeley Only Offer a BA?

    I know that this question has been answered before, but what is the difference between a BA and a BS in physics? Specifically in reference to UC Berkeley. Berkeley only has a BA in physics, but it is not like this is a second rate degree, considering that Berkeley is known for its physics...
  35. C

    Difference in Brightness between Two Bulbs

    Homework Statement Two lightbulbs of resistance R1 and R2 (R2 > R1) are connected in series. Which is brighter? What if they are connected in parallel? Explain. Homework Equations P=V^2/R P=I^2R The Attempt at a Solution I know the solution. In series, P1=I^2R1 < P2=I^2R2, so R2 is...
  36. Peter25samaha

    What's the difference between Δ and d in physics ?

    Is the acceleration : a=Δv/Δt equivalent to a=dv/dt ?? Anx what's the difference between Δ and d and can i use Δ when i want ? a=d2x / dt2 Can we write the same using Δ ?
  37. G

    B Phase difference in standing wave

    Can someone explain why the phase difference is zero when the there is equal number of nodes between the two vibrating particles. Thank you
  38. F

    What is the Difference in Pressure Between Two Points Using a Pitot Tube?

    Homework Statement This is a pitot tube . The diffrence in height of the liquid at 2 sections is y = 0.2m ...is the pressure difference between P1 an P2=0.2(density of mercury )(g) ? Homework EquationsThe Attempt at a Solution i don't have the ans for this question , is my answer correct ?
  39. A

    Conical Surface Potential Difference

    Hey guys! The question is related to problem 2.26 from Electrodynamics by Griffiths (3ed). 1. Homework Statement A conical surface (an empty ice-cream cone) carries a uniform surface charge σ. The height of the cone is h, as the radius of the top. Find the potential difference between points a...
  40. J

    Sign of potential difference?

    Homework Statement A particle begins in a region where positive and negative charges are uniformly distributed and ends up in a region near a negatively charged plate. What is the sign of the potential difference in this case? Homework Equations N/A The Attempt at a Solution I assumed this...
  41. nmsurobert

    Phase Difference at Air-Glass Interface: 30°, λo=1μm

    Homework Statement A plane-wave is incident on an air-glass interface at 30° as shown below. Calculate the phase difference between A and B. Assume λo=1μm. attatched is an image that looks like this. ________________________ --------------------------- A --------------------------- B...
  42. I

    Difference between the various COP formulae

    Homework Statement Homework Equations N/A The Attempt at a Solution My question is a simple one: how is the above equation for COPref different to the COPref equations I've already encountered (such as COPref = Qc/Win = (h1-h4)/(h2-h1). Is the above just a different form of these? Or is the...
  43. Docscientist

    Why Do We Use AMU Instead of Grams in Mass Spectrometry?

    Atomic mass,molecular mass and formula mass: how are they different and how are they used differently ?
  44. T

    Difference between density and unit weight with same units

    In my lectures and notes my professor keeps writing out density as lbs/ft3 and unit weight as lbs/ft3. For a material such as concrete it could have a density of 167 lbs/ft3 but a unit weight of 103 lbs/ft3. I am confused as to how these two values are different even though they have the exact...
  45. vetgirl1990

    Phase difference between waves in two-slit model

    Homework Statement In a double slit experiment, the distance between the slits is 0.2mm and the distance to the screen is 150cm. What is the phase difference in degrees, between the waves from the two slits arriving at point P, when the angular distance of P is 10 degrees relative to the...
  46. vetgirl1990

    Finding the angle of phase difference - two slit model

    Homework Statement Light of a wavelength 548nm illuminates two slits separated by 0.25mm. At what angle would one find the phase difference between the waves from two slits to be 2 rads? Homework Equations σ / λ = ΔΦ / 2π σ: path difference λ: wavelength Δφ: phase difference The Attempt at a...
  47. S

    A Finite Difference solver for 2D Elasticity equations

    Hi I've been trying to get a simple solution to the 2D Navier-Lame equations using finite difference on a rectangular grid. I want to see the displacements, u and v, when a simple deformation is imposed - e.g. top boundary is displaced by 10%. The equations are as follows: \begin{eqnarray*}...
  48. T

    Difference between optically active and inactive compounds

    Any polarised light's plane is shifted while passing from one medium to another for refraction. So, optically active or not, a solution of any compound will cause refraction because of its density. Then what's special in an optically active compound?
  49. netsky

    Difference between ohmic and non ohmic resistors

    I was reading about ohmic and non-ohmicresistors, but I'm unsure as to what thedifference between them is. I understand that ohmic devices have a constantresistance, meaning the voltage-current graph produced for it will show a straight line and that non-ohmic devices have a changing resistance...
  50. S

    I What is the Significance of Isospin Components in Particle Physics?

    Over lots of studying on particle physics, i came across all kinds of different types of spins, like isospin, spin, weak isospin, and i even learned that there are 3 components for each isospin. Can someone tell me why we need these things and what is special about each component of weak isospin...
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