parts Definition and 817 Threads

  1. E

    Circuit schematics for standard parts

    Circuit schematics for "standard" parts Hi, I graduated from computer engineering, but I want to learn more about circuits. I did get the chance to play with Quartus 2 in some of my courses and I was wondering if there is a place where I can learn about the circuit schematics for the most...
  2. D

    Kinetic energy of a vehicle's constituent parts

    Homework Statement I have set myself the problem of modeling a KER's technology applied to road cars. I am looking to establish the kinetic energy of a vehicle corresponding to a specific drive cycle for instance the NEDC or similar. I have distance speed and time data for the drive...
  3. A

    What is the formula for integrating (a^2 - x^2)^n using integration by parts?

    Homework Statement Use integration by parts to derive the formula: \int (a^2 - x^2)^n dx = \frac{x(a^2-x^2)^n}{2n+1} + \frac{2a^2n}{2n+1}\int \frac{(a^2 - x^2)^n}{(a^2 - x^2)} dx + C Homework Equations Integration by parts general formula ∫udv = uv - ∫vdu The Attempt at a...
  4. A

    Calculate the molar enthelpies of reaction occuring in parts A and B

    Homework Statement Part A: Mass of Mg (s) = 0.31 g Initial temperature of calorimeter contents = 24.1 C Finial temperature of calorimeter contents = 36.8 C Part B: Mass of MgO (S) = 1.22 g Initial temperature of calorimeter contents = 24.0 C Finial temperature of calorimeter contents = 31. 9 C...
  5. B

    Show that the real and imaginary parts of the wavenumber, k, are given by

    Homework Statement Show that the real and imaginary parts of the wavenumber, k, are given by k(real)=[sqrt(epsilon(real))]omega/c and k(imaginary)=[epsilon(imaginary) *omega/(2c sqrt(espilon(real))) The Attempt at a Solution k^2= mu epsilon omega^2 (1+(i g/epsilon*omega)) k^2...
  6. M

    Why Does Voltage Drop When a Dielectric Is Inserted in a Capacitor?

    Homework Statement This was done on my Physics II class, ans the Professor has'nt want to explain it to usA 2 Circular Metallic Plate Capacitor, maybe of a diameter of 15cm, was connected to a constant sourch of DC voltage until it was charge to 10Volt, after this the source was DISCONNECTED...
  7. L

    Discovering the Prime and Factored Parts of Positive Integers

    Is there a way within reasonable errors to say what part of the positive integers are prime and what part is factored greater than one? Oh course one is a factor of all numbers greater than zero. Yeats ago playing around a floating constant became known to me. to the tenth decimal place is...
  8. A

    Integrating by Parts: Solving ∫r^3/(4+r^2)^(1/2) dr

    Homework Statement ∫r^3/(4+r^2)^(1/2) dr Homework Equations ∫udv=uv-∫vdu The Attempt at a Solution I know that integration by parts must be used. I tried doing it with 4+r^2 as u, but kept running into issues..then I got an answer but it appears to be wrong. I guess I am not sure...
  9. lonewolf219

    Checking solution to integration by parts with e

    Hi, I'm wondering how to integrate 4xe^(4x). I got: 4[1/4xe^(4x)-1/16e^(4x)+c] ? which reduces to xe^(4x)-1/4e^(4x)+c Is this the correct integral? Thanks.
  10. M

    Integration by Parts: Solve Integral of (1-x)

    Homework Statement Solve integral \int^{1}_0(1-x)\frac{d}{dx}\frac{\sin Cx}{C}dx Homework Equations \int udv=uv-\int vdu The Attempt at a Solution u=1-x dv=\frac{d}{dx}\frac{\sin Cx}{C}dx What is v? How to integrate \frac{d}{dx}\frac{\sin Cx}{C}dx?
  11. T

    Integration by parts, help me understand why the integration limits changed.

    Homework Statement I am doing self-study. I am on problem 5.6 #27 in the Stewart text 3rd E. I don't understand why the integration limits changed after the given substitution. The given substitution was: x=θ^2 dx=2θdθ Homework Equations Please see attachment. The Attempt at...
  12. X

    Random Question about designing parts

    Hello all! So if I wanted to make and order a part to a device I am designing, where would I go to do that? I know this may seem like a weird question but here is my situation. My brother has two graphics cards in his computer and there is a VERY thin space between them, and because of that...
  13. S

    Never ending integration by parts

    Homework Statement \int_0^\infty{ \frac{1}{x} e^{-x}} Homework Equations Integration by parts \int{u dv} = uv - \int{v du} The Attempt at a Solution u = \frac{1}{x} du = \frac{1}{x^2} dx v = -e^{-x} dv = e^{-x} dx -\frac{1}{x} e^{-x} - \int_0^\infty{-e^{-x}...
  14. K

    Separating real and complex parts of a number

    Homework Statement Hello, I am supposed to express the and the phase part of expression: \displaystyle{S=\frac{k}{\sqrt{1+i\gamma_0}} \cdot exp\left(\frac{z}{1 + i\gamma_0}\right)} Homework Equations The answer should be in the form: \displaystyle{S=a(\gamma_0) \cdot...
  15. S

    Finding Integral Re/Im Parts of Complex Numbers

    Homework Statement Find four complex numbers z each with the property that Re(z), Im(z), Re(z-1), Im(z-1) are all integers, where Re and I am denote the real and imaginary parts respectively of a complex number. Homework Equations Maybe 1/z = \frac{\bar{z}}{|z|2} ? On my screen that code...
  16. Z

    How do you integrate this function (not by parts)?

    Homework Statement integrate: r2*exp(i*k*r - r2/a2) from -infinity to +infinity (in terms of r) Homework Equations relevant integration table The Attempt at a Solution not sure what this function or the method to solve this function is called
  17. Jonnyb42

    Quantum Mechanics - Leonard Susskind on Integration by Parts

    I'm watching the video series on Quantum Mechanics taught by Leonard Susskind, (from Stanford). On Lecture #3, Dr. Susskind says that integration by parts is: ∫FG' = -∫GF' However from what I know integral by parts to be, there i missing a +FG on the righthand side, or something... since I...
  18. C

    Finding a Plastic Parts Heater for Safe & Quick Warm-up

    Hello, I am looking for something to keep plastic parts warm and pliable. We have plastic discs that need metal pins snapped into some grooves and they snap wayyy to tight. We checked with a vendor and the material is still within spec, but I cannot change the material It takes one minute...
  19. J

    What Parts of The Classics were Removed from Education in the Progressive Era?

    According to Wikipedia in the progressive era the classics were removed from education. I know this isn’t completely true (At least world wide) because I learned a small amount of Greek Mythology (I live in Canada) in school. However, there was no study of Plato or any amount of philosophy at...
  20. N

    Integrating Tangent by parts; 0 = -1

    Homework Statement The question is what has gone wrong in this proof, it is worth noting this a definite integral between pi/6 and pi/4: ∫ tan(x) dx = ∫ sin(x)/cos(x) dx Let u = 1/cos(x) and dv = sin(x) dx So du= sec(x)tan(x) and v = -cos(x) When we substitute back in we get: ∫ tan(x)...
  21. K

    Intergration my parts. Reduce.

    Homework Statement S P^4 e^-P DP Homework Equations My parts. The Attempt at a Solution I know you can do u = P^4, and DV = e^-P Then, you get du = 4P^3 dx and V = -e^-P -P^4 e^P + S 4P^3 e^-p dx Now, I can just repeat that for the intergral until I get to were the P...
  22. O

    Ordinary Diffusion and integration by parts

    Homework Statement For ordinary 1D diffusion show that the mean value of the square of the position is equal to 2Dt Homework Equations \left\langle {x^2 \left( t \right)} \right\rangle \equiv \int\limits_0^\infty {x^2 p\left( {x,t} \right)dx} \frac{\partial }{{\partial t}}p\left(...
  23. S

    Mastering Integration by Parts: Solving ∫(2x-1)e^(-x) dx Made Easy

    Homework Statement ∫▒〖(2x-1)e^(-x) 〗 dx I don't want to butcher this but I know you use integration by parts, I just don't know how to do this one in particular because i is one of the simple ones I was told. Please Help
  24. P

    What Is the Correct Approach to Integrate 2*arctan(x) by Parts?

    Homework Statement problem: \int2arctanx dx 2\intarctan dx u=arctanx du=1/(1+x2) v=x dv=dx xarctanx-\intx/(1+x2) integrate by parts a second time... u=x du=dx v=arctanx dv=1/1+x2 xarctanx-\intarctanx My final answer I get it 2xarctanx-2xarctanx+2/x2+1 which is...
  25. T

    Solving integration by parts using derivatives vs differentials?

    What is the difference? I was pretty bored last night so I got onto Yahoo Answers and answered a few calculus questions. It was a simple integration by parts question: \intxsin(x) dx I solved as: u = x du = dx dv = sin(x) dx v = -cos(x) uv - \intvdu -xcos(x) + \intcos(x)dx =...
  26. R

    Integrate by parts the d'alembertian of a 4-variable function

    Can you please tell me how to integrate by parts the d'alembertian of a 4-variable function over a volume dx * dy * dz * dt. I have stumbled upon this seemnigly simple exercise on my way to understanding QFT of scalar fields.
  27. U

    What Went Wrong in My Integration by Parts?

    Here I used integration by parts to try to solve an integral (I got it wrong, it seems), I know this has no "simple" solution, but, can anyone explain me exactly what did I do wrong? Here is what I did...
  28. P

    Do entangled systems have parts?

    Some say that there are parts but their properties depend on the whole. But if we cannot assign properties to the 'parts' of an entangled system, what can it be to be a 'part' or any kind of entity in the first place? Can we say that there are parts but that they are not independent? What can...
  29. K

    Continuously variable gearboxes do they exist as separate parts?

    I'm sure many of you are aware of CVTs or continuously variable transmissions. Many of you are also aware, I am sure, of off-the-shelf gearboxes which you can use to step up/down (typically) the output of a motor. Do they have a device which allows a variable gear ratio, especially one...
  30. N

    Understanding Integration by Parts: Solving Tricky Integrals

    Homework Statement Hi There is a step in my book, which I can't follow. It is the following \int_0^1 {w\left( {\frac{{d^2 u}}{{dx^2 }} - u + x} \right)dx} = \int_0^1 {\left( { - \frac{{dw}}{{dx}}\frac{{du}}{{dx}} - wu + xw} \right)dx} + \left[ {w\frac{{du}}{{dx}}} \right]_0^1 I...
  31. A

    Solve Integration by Parts: y' = x.y.cos(x^2)

    Homework Statement Find the solution to: y' = x.y.cos(x^2)Homework Equations Integration by Parts method.The Attempt at a Solution Step 1 (dy/dx).(1/y) = x.cos(x2) (1/y) dy = x.cos(x2) dx Step 2 Integrate both sides. ln|y| = integratal of [ x.cos(x2) dx ] Step 3 Using integration by...
  32. D

    How Does Integration by Parts Move from the Second to the Third Line?

    Somebody could explain me, how of the second line arrive to the third one? in my book says that is integration by parts, please helpppp :eek:
  33. H

    Proof that d/dx is anti-hermitian by integration by parts

    The attempt at a solution \begin{equation*} \begin{split} \ -\ i\int\psi^* \frac{\partial{\psi}}{\partial x}= \\ -i(\psi^*\psi\ - \int\psi \frac{\partial\psi^*}{\partial x})\space\ (?) \end{split} \end{equation*} I thought \psi^*\psi\ = \ constant\neq\ 0. However, it vanishes in...
  34. B

    Parts Produced Vs Total Downtime

    Parts Produced Vs Total Downtime - Graphical Interpretation Hi all! I'm working on a project analyzing downtime for a manufacturing floor. The department makes between 6 and 8 millions parts per month with 10-18 thousand minutes of unplanned downtime collectively (changeovers, maintenance...
  35. Spinnor

    Spin of a proton from its parts.

    Is there a simple way to see how all the spin and orbital angular momentum of a protons parts (quarks and gluons) sum precisely to that of a spin 1/2 fermion? Thanks for any help!
  36. K

    How Can I Remove Imaginary Parts from a Complex Number Expression?

    Hi all, I have this expression containing complex numbers and I wanted the expression to be displayed with real parts only. How can i do this? For instance, the original expression is, eqn = (16.0001+3.16141*10^-21 i)-(0.00860351-1.16927*10^-18 i) Ao[1]+(0.00537811-4.47536*10^-19 i)...
  37. S

    Integration by Parts & Change of Variables Proof

    I'm just curious about the proofs of Integration by Parts & the Change of Variables formula as given in this book on page 357. I think there are a lot of typo's so I've uploaded my rewrite of them but I am unsure of how correct my rewrites are. If someone could point out the errors & why I...
  38. S

    Integration by Parts: Finding the Center of Gravity in a Fan Blade

    Basically I have answered a question using the integration by parts formulae to work out the centre of gravity inside a fan blade using :- v.du/dx = v.u - u. dv/dx with the integral limits of 0 ==> 20 when v = x then dv/dx =1 when du/dx = 0.3 sinx then u = 0.3cos x and sub this into...
  39. M

    Integrating Trigonometric and Exponential Functions with Integration by Parts

    Homework Statement Take the integral of the following: 1. ln(2x+1) 2. arctan4x 3. ecosxsin2x evaluated from 0 to pi The Attempt at a Solution 1. took the derivative of ln(2x+1) and integrated dx. my solution was: xln(2x +1) + x + [(2x + 1)-2]/2 + C The books answer was...
  40. C

    Recycling parts from other electronics

    Hi everyone, first time poster on Physics forum here. I'm working on a school project to make a device to read QR code. I'm strapped for cash so I'm trying to figure out if I can recycle some parts from used electronics. Looking for the following parts: - a graphic LCD display - an arduino...
  41. W

    Integration by parts & inv. trig fxn

    Homework Statement \int xarcsin2xdx 2. The attempt at a solution Can someone explain to me what is happening at step 2? I understand how the integration by parts was done, but where does the (1/8) or (2x) come from?
  42. W

    Applying Integration by Parts & Trig Substitution

    Homework Statement \int\sqrt{4+9x^{2}}dx Homework Equations Pythagorean Identities? The Attempt at a Solution I find it sort of cumbersome to use the special formatting here, so I hope it is okay that I just photocopied my work on paper. You can see how far I made it, but...
  43. F

    What Does an Uncertainty of 8 Parts in 1010 Mean in Experimental Results?

    Trying to answer a question that state an experiment results shows uncertainty of 8 parts in 1010. Can anyone shed some light on the meaning. I don't understand. Thank you
  44. S

    Integration by Parts: Solving Integrals without Laplace Transforms

    1. How to solve integral of (1/(t2-t))dt 2. to be solved without using laplace transforms 3. integral of( uv)= u*(integral of v) -integral of ((u')*(integral of v)) ... right? integral of (1/t^2-t) = integral of (1/t)*(1/t-1)dt = (1/t-1)*(log t) - integral((-1/(t-1)2*logt ...i don't...
  45. K

    Integration by parts and infinity

    Homework Statement integrate (x*2e^x)/(2e^x-1)2 from x=0 to infinity Homework Equations The Attempt at a Solution let t=2e^x-1 => x=ln((t+1)/2) dt = 2e^x dx Thus equation is now integrate (ln((t+1)/2))/t^2 dt from t=1 to infinity Then let u = (t+1)/2 => 2du=dt Equation now...
  46. D

    Integration by parts, don't quite know how to arrive at the given answer

    I am assuming that the solution was arrived at through integration by parts, however I am not able to completely work through it. First given: cB= XB/Vm the next step shows the solution to dcB given as: dcB=(1-dlnVm/dlnxB)(dxB/Vm)
  47. N

    Solving sin z=2: Equating Real and Imaginary Parts

    Homework Statement Solve sin z=2 by (a) equating the real and imaginary parts (b) using the formula for arcsin z. Homework Equations (a) sin z = sin x * cosh y + i * cos x * sinh y arccosh z = log[z + sqrt(z^2 - 1)] (b) arcsin z = -i * log [i * z + sqrt(1 - z^2)] The...
  48. B

    Real parts of two analytic functions are equal?

    Homework Statement Suppose f and g are analytic on a bounded domain D and continuous on the domain's boundary B. Also, Re\left(f\right) = Re\left(g\right) on B. Show that f = g + ia, where a is a real number. Homework Equations The maximum modulus principle states that Re\left(f\right) and...
  49. P

    Why does the LPG cylinder has to be two parts welded together

    Am a second year be student.While in a discussion in class my professor posed this question to us"Why does the LPG cylinder has to be two parts welded together".I tried searching it in net but coudn't kinda get the answer so can somebody explain it to me... And since am newbie to the...
  50. vmr101

    I(n) = ∫sin^n (x) dx (integration by parts)

    Homework Statement i)Use integration by parts to express: I(n) = ∫ sin^n (x) dx in terms of I(n-2). ii) Hence show that ∫(π/2 for top, π/4 for bottom) 1/[sin^4 (x)] dx = 4/3 Homework Equations Reduction Formula and Trig Identity [sin²(x) + cos²(x) = 1] π = pi The Attempt at a...
Back
Top