parts Definition and 838 Threads

In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement. Commonly used are parts-per-million (ppm, 10−6), parts-per-billion (ppb, 10−9), parts-per-trillion (ppt, 10−12) and parts-per-quadrillion (ppq, 10−15). This notation is not part of the International System of Units (SI) system and its meaning is ambiguous.

View More On Wikipedia.org
Recent contents Top users
  1. P

    Integration by parts (i think)

    Greetings all, here goes... The integral of (xe^(x))/((x+1)^(2)) Thanks
  2. RadiationX

    Incomplet notes on integration by parts

    i'm trying to complete my notets from my calculus II class. my professor showed us how to do the following integral using integration by parts but I'm not following his reasoning could some one fill me in on what I'm missing. thanks in advance. \int^{\pi}_03x\sin\frac{x}{2}\\{dx} let \...
  3. S

    Cut a metal like aluminium in very small parts

    Does anyone know what tools are available to cut a metal like aluminium in very small parts and to join two parts together and still get a neat finish?
  4. Z

    Which term should be chosen for u(x) in integration by parts?

    ok i`m really struggling with the concept. I've been asked to find the indefinite integral of; \int \frac{x^2}{(2+ x^3)} dx so before i beg for the answer could someone confirm that i`ve got the right rule to solve this; \int u(x) v'(x) = [ u(x) v(x)] - \int v(x) u'(x) if this...
  5. S

    Integration by parts when a limit is infinity.

    I'm having a tough time trying to do integration by parts with one of my limits being infinity. My Integral looks like: \int_0^\infty x^z e^{-x} dx with z = \frac{-1}{\pi} Now if I let u = e^{-x} and dv = x^z dx, I will have: du = -e^{-x} dx and v = \frac{1}{z + 1} x^{z + 1} and...
  6. M

    How can I integrate e^-x sinx using parts?

    I've got a function \int e^{-x}sinx dx From what I know, only functions which has one or more products with a finite number of successive differentials can be evaluated using integration by parts. Because for \int v du in our choice of du, we want to cut down on the number of times we have...
  7. Y

    Done by parts integral and simplify

    i have to integrate the next: (x^2)(e^x)dx/((x+2)^2) It should be done by parts. How I can simplify it? Is (4x+4) (e^x) dx/(x+2)^2 easier to be integrated?
  8. J

    I have no idea how to integrate by parts

    I don't think anyone in class understands it, we went over it so quick. The only thing I seem to get is that uv - (integral) vdu = (integral) udv. You are supposed to assign u, v, dv and du, but how do you know which is u and which is v? What is the difference between du and dv? Are you...
  9. Loren Booda

    Does an infinite universe always repeat its parts?

    Can an infinite universe with infinitesimal detail be nonrepeating?
  10. E

    Extracting Parts of Video Files: What Programs are Available?

    I have never done this before, but what programs are available out there so that i can extract certain parts from a movie in .mpeg or .avi format? Like in soundforge i can open an audio file and extract any waveform and copy it to a new window and process it, can i do the same for a video...
  11. T

    What is the best approach for Integration by parts?

    I am usually alright once I figure out how to split up the integral into u: du: v: dv: so i can simply do uv-\int v*du but I keep messing up on there I will post some examples if I can find them and if someone could help me that would be great \int (ln(x))^2
  12. T

    Figuring Out an Odd Function With Different Parts Along x-Axis: Help Needed!

    I just can't seem to grasp this! I have no problems finding out if a function let's say x-2x^2 is an even or odd function, but when the function is defined differently along different part along the x-axis then I don't understand anything! This function: f(x)=\left\{\begin{array}{cc}0 &\mbox{...
  13. M

    Stuck on Integrating e^(x^3) x^2?

    Hi, I've actually got a problem here. How do I evaluate \int e^x^3 x^2 dx I have problem when doing integration by parts of finding \int v du since if I integrate v du, i'll get another expression which i have to integrate by parts again, and this goes on and on ! (its meant to...
  14. D

    Medians & Congruent Triangles: Exploring Proportional Parts

    If a line in a triangle is a median, does it cut the triangle into two congruent triangles?
  15. W

    How Does Integration by Parts Simplify \(\int 8x^2 \cos(2x) \, dx\)?

    i will use "\int" as integral signs, cause latex seems to be down. uv - \int v*du \int 8x^2cos(2x)*dx u = 8x^2 du = 16x*dx dx = 1/16 dv = cos(2x) v = 1/2sin(2x) plug in what i found for the formula 8x^2*1/2*sin(2x) - \int 1/2*sin(2x)*16x take out the 1/2, because it's a...
  16. K

    Help on a problem with multiple parts, please

    hey i was wondering if anybody could show me how to do a problem that contains multiple parts: 55. A 3.00 kg block starts from rest at the top of a 30.0° incline and accelerates uniformly down the incline, moving 2.00 m in 1.50 s. a. Find the magnitude of the acceleration of the...
  17. B

    Why Does My Integration by Parts Solution Differ from the Textbook's?

    Ok so I was attempting to solve an integration by parts problem and somewhere along the line I got stuck. Here's the problem: \int^{\infty}_{2} {x^2 e^{-x} - 2xe^{-x} After using integration by parts twice I came up with this: 2xe^{-x} - x^{2}e^{-x} + 2e^{-x} \vert^{\infty}_{2} But...
  18. C

    Atom Part Radii: Electron, Proton, Neutron

    Do anybody know the radius of an electron, proton, or neutron? I understand there are smaller things like quarks, and everything, but as a general size, does anybody know the radius of these parts of an atom?
  19. C

    Integration: Choosing U-Sub vs. Parts

    when doing integration, how do you know if you should use u-du substitution or integration by parts if the problem doesn't state it?
  20. W

    Integration by Parts: A Powerful Tool in the Theory of Distributions

    \int 4x cos(2x) using integration by parts... u=4x du= 4 dv=cos(2x) v=cos(x)sin(x) using the formula uv - \intv*du... 4x*cos(x)sin(x) - \intcos(x)sin(x)*4x hmm i can't seem to finish this problem, can someone help? and am i doing it correctly so far?
  21. C

    Help Solving Integration by Parts Problem in Calculus 2

    hi, i would like help on a problem i am currently stuck on. \int(e^x)/(1+e^(2x))dx <-- it's suppose to be \int (e^x)/(1+e^(2x))dx using integration by parts, here's what i done: u=e^x du=e^x dv=(1+e^(2x)) v = (need to use anti-differentiation, which i don't remeber...) can i...
  22. Z

    Wormholes to lead into different parts of space

    Can anyone please expalin to me how it's possible for wormholes to lead into different parts of space, and even time? Thanks.
  23. R

    Having trouble with Integration by Parts

    I'm real stuck with this problem of mine in The Calculus 7 by Leithold \int arctan \sqrt{x} dx Since there is no elementary formula for integration of an inverse trigo function, we cannot manipulate the integrand in such a way as to integrate easily with one step of Integration by...
  24. R

    Build a Crystal Radio - Needed Parts & Where to Find Them

    has anyone here ever built a crystal radio? what parts would i need and where can i get them? in the physics forum they said one could be constructed to run off the radio waves themselves, which is the kind i would like to build. thanks
  25. S

    Mastering Integration by Parts: Tips and Tricks for Solving Difficult Problems

    I'm stuck on this one problem. If anyone can aid me, I would greatly appericate it. http://home.comcast.net/~personalcomp1/Impossible_calc_problem.JPG I scaned in the problem sooo there's the place to view it. Thanks
  26. D

    Solve Integrals by Parts: 2xln(3x)

    Please help me with this problem using the "integration by parts" method. ∫2x times natural log of (3 x) dx Appriciate it!
  27. R

    Biology- parts of fetal pig brain

    Tommorrow I have a practical on the dissection of a fetal pig I have been doing all week. Today I removed the brain- intact out of the pig. I have completely forgotten a couple parts of the brain- and would like to remember them when I have the test tommorrow. Since the pig brain is similair in...
  28. wolram

    Parts List for My New PC - What Do You Think?

    this is a list of parts i plan to use in my new pc what do you think? asus a7n-8x-x n- vidia motherboard amd anthlon xp2500 plus 333 fsb akasa silver mountain heavy duty fan 2 sticks pc2100 ddr dimm memory 60 gb hitachi deskstar 7k250 7200rpm ide hdd screwless midi tower 350 watt psu i...
  29. Rockdog

    Electrostatic force problem help with vector parts

    I've included a picture. Two charges Qc and -Qc(Qc = 4 µC) are fixed on the x-axis at x = -7 cm and x = 7 cm, respectively. A third charge Qb = 5 µC is fixed at the origin. A particle with charge q = 0.3 µC and mass m = 5 g is placed on the y-axis at y = 14 cm and released. There is no...
  30. Rockdog

    Electrostatic force problem help with vector parts

    I've included a picture. Two charges Qc and -Qc(Qc = 4 µC) are fixed on the x-axis at x = -7 cm and x = 7 cm, respectively. A third charge Qb = 5 µC is fixed at the origin. A particle with charge q = 0.3 µC and mass m = 5 g is placed on the y-axis at y = 14 cm and released. There is no...
  31. S

    Integration of Parts Calculus help

    Hey all-- I had an Integration of Parts quiz today and got stuck on a few problems-- was wondering if you could explain the steps involved in solving these integrals: int( (sin(3x))^3 * (cos(3x))^3 dx) and int( (tan(4x))^4) dx) thanks!
  32. jimmy p

    Why Do Manufacturers Choose Such Odd Sizes for Products?

    How come when manufacturers pre-size things for the mould, they ALWAYS come up with such random numbers! For example today, i was looking for a new CD rack, and all i saw were things like "holds 64 cds", "can store up to 92 cds", holds "140 cds and 14 videos", holds "312 cds and 41 DVDs"...
  33. K

    How to Integrate by Parts Twice for e^3x cos(x)?

    I am studying for a midterm, was browsing over an old midterm and found this question \int e^{3x} \cos{(x)}\; dx Can't figure it out, help would be appreciated
  34. Greg Bernhardt

    I have no mechanical parts but I take you for a ride.

    I have no mechanical parts but I take you for a ride. I won't be ridden in a desert or on a mountainside. Each time the ride is different - no two are ever the same. Some are wild and treacherous and some are very tame. What am I?
  35. R

    Pivoting Stickstuck on two smaller parts

    A picture has been included for your viewing pleasure. A stick of uniform density with mass M = 7.7 kg and length L = 0.6 m is pivoted about an axle which is perpendicular to its length and located 0.16 m from one end. Ignore any friction between the stick and the axle...
  36. P

    Understanding the Notation of the Parts Formula

    Can someone explain the notation of the parts formula pls.,.. it's very very confusing. int [u dv] = uv - int [v du] ... very confuzing, ... made me think it was the product formula lol. And I still don't understand what does dv and dx and all these d stuff standfor in integrals...
  37. I

    How Can I Solve the Integral of Sin^8x Using Integration by Parts?

    Hi can anyone help me solve this integral, I'm having trouble with this one? the integral is: int(sin^{8}x.dx)->upper limit=pi ->lower limit=0. Q) Evaluate the integral exactly using integration by parts to get a reduction formulae for int(sin^{n}x.dx)
  38. J

    Why does water spin in different directions at different parts of the world?

    Why does water spin in different directions at different parts of the world? Also, which way does it spin on the equator?
Back
Top