Line Definition and 1000 Threads

  1. K

    B Calculating Length Along X-Axis for a Rotating Line

    Hi (I hope this is the right place to post this - sorry if it's not) Say I have a line (in the graphic is shown a 10mm but it could be any length) and it rotates around a point at one end. What is the formula to get the length along the x-axis directly under the other end of the line. In the...
  2. Spinnor

    B In Cosmic First, Scientists Spy a Star's Snow Line

    http://www.space.com/33410-star-snow-line-seen-for-first-time.html From there, For the first time, astronomers have caught a glimpse of the water snow line around a star — the point in the young star's orbiting disk of debris where snow and ice first appear. Normally, that boundary huddles...
  3. C

    Line Integral Homework: How to Solve for the Total Length of a Curve

    Homework Statement i'm not sure what is line integral... Homework EquationsThe Attempt at a Solution Does it mean total length of line under the curve?
  4. T

    I Are all line segments truly equal?

    Hello, If someone takes two segments, one longer than the other, it is naturally assumed that the longer one is most definitely longer than the other. However, if the longer segment is put at an angle with the other to make a triangle, suddenly someone can draw a one to one correspondence...
  5. Labyrinth

    I Function for line segment configuration between dots

    If I have n dots, how many configurations exist for lines that connect them, including no connections? For example, if I have 0, or 1 dots I believe this should be 0 since no connections are possible (or perhaps I should consider the single dot as having a single connection to itself?) If I...
  6. M

    Determining the force on a loop cause by an infinite line

    Homework Statement An infinitely long line of current $I_1=6[A]$ is following along the positive z-axis in the direction of +$\hat{a_z}$. Another current is following a triangular loop counter clockwise from the points A(0,2,2), B(0,6,2) and C(0,6,6). Homework Equations To start I applied...
  7. RaulTheUCSCSlug

    Creating a Line Following Robot with Arduino and Mindstorms: A Six Sigma Project

    I'm looking to build an Arduino that is capable of following a line depending on a colored strip on the ground, either black or white. I think I might use a LDR, but not quite sure where to even start to be honest. My office is having an Arduino contest, and I just want the Arduino to carry...
  8. C

    Finding the geodesic equation from a given line element

    Homework Statement We've got a line element ds^2 = f(x) du^2 + dx^2 From that we should find the geodesic equation Homework Equations Line Element: ds^2 = dq^j g_{jk} dq^k Geodesic Equation: \ddot{q}^j = -\Gamma_{km}^j \dot{q}^k \dot{q}^m Christoffel Symbol: \Gamma_{km}^j = \frac{g^{jl}}{2}...
  9. S

    B Question about the math involved in E-field calculations

    When calculating the electric field from a point above a line of charge using coulomb's law, the integral that comes up is of the form \int { \frac { dx }{ { x }^{ 2 }+{ a }^{ 2 } } } . But if the point we were asked for is right in the middle, the horizontal (cosine) components cancel out...
  10. S

    Line integral convert to polar coordinates

    Homework Statement I need to find the work done by the force field: $$\vec{F}=(5x-8y\sqrt{x^2+y^2})\vec{i}+(4x+10y\sqrt{x^2+y^2})\vec{j}+z\vec{k}$$ moving a particle from a to b along a path given by: $$\vec{r}=\frac{1}{2}\cos(t)\vec{i}+\frac{1}{2}\sin(t)\vec{j}+4\arctan(t)\vec{k}$$ The Attempt...
  11. JulienB

    Mass point sliding on a rotating line (Lagrangian)

    Homework Statement Hi everybody! I have a crazy problem about Lagrangian on which I've been working on for two days without being able to figure it out. I have a solution, but I think there is a flaw in it. First here is the problem: A line rotates with constant angle velocity ##\omega##...
  12. S

    Three/four sprockets in horizontal line can be run by chain?

    Hello people, I have a serious design problem for designing a sprocket-chain system. I want to know that can three sprockets as in picture (in attachment) can be rolled by a chain? The main concern is for middle sprocket it have few teeth above and few teeth in bottom connected to chain. The...
  13. M

    LaTeX Plotting a Line in TikZ: Investigating Unexpected Behavior

    Hi PF! I'm plotting a line in TikZ using the following code \draw[domain=0:25,samples=100,color=blue,variable=\x,line width=1.5] plot (\x,{0.9924686128641765 - 0.023406305144575135*\x - 0.0006942621866861979*\x^2 - .000001925581045950128*\x^3}); The largest zero is 24.0699 but latex is...
  14. T

    Line integral over vector field of a shifted ellipse

    This is part of a larger question, but this is the part I am having difficulty with. I have had an attempt, but am not sure where I am making a mistake. Any help would be very, very appreciated. 1. Homework Statement Let C2 be the part of an ellipse with centre at (4,0), horizontal semi-axis...
  15. S

    MHB Slope of Line Intersecting (2,2) & (6,7)

    If a line intersects both points (2, 2) and (6, 7), determine its slope.
  16. S

    Line Integral over circle region

    Homework Statement Evaluate ∫c (x + y) ds, where C is the circle centred at (1/2, 0) with radius 1/2. Homework EquationsThe Attempt at a Solution parametrise x=1/2cos(t) y=1/2sin(t) 0≤t≤2π ds=√dx2+dy2 =√(1/2)2-sin2(t)+(1/2)2cos2(t) =√-(1)2(1/2)2sin2(t)+(1/2)2cos2(t)...
  17. D

    Mathematical proof (Drawing a help line)

    Homework Statement I'm doing quite a strict proof in school. Where we should proof something and use mathematical language and symbols. Homework Equations The Attempt at a Solution To proof what I have to proof I need to draw some help lines. As for instance the "red" one I did from A to B...
  18. S

    Calculating Line of Sight and Obstruction in Restaurant Redesign

    I'm working on re-designing a restaurant by the sea. I'm a interior decorator so I know very litle about physics. Here's my question: let's say you're in the back of a room with 90 meters of floor in front of you. You are 7 meters above ground but your eyes are only 10 cm above the floor. I've...
  19. putta

    How to fix pressure transducer to Hydraulic line

    Dear Experts, I want to put new feature for my hydraulic pressing station (capacity:-350TON). present it existing with dial type pressure indicators. and directional propositional valve 3/4 for pressure lines. here value are made DAIKIN (JSO-G03-2CB-10) this model top side Alean key thread...
  20. Geek007

    Does Microwave support only Line of sight communication LOS?

    Hi there, Wifi uses either 2.5 GHZ band or 5 Ghz band and these bands lie in Microwave in EM spectrum. As i read in books, Microwaves are propagated using line of sight (LOS) technique, so sending and receiving antennas should need to be aligned accordingly. But WiFi signals are broadcasted...
  21. Eclair_de_XII

    Finding the equation of a tangent line in polar coordinates?

    Homework Statement "Slopes of tangent lines Find the slope of the line tangent to the following polar curves at the given points. At the points where the curve intersects the origin (when this occurs), find the equation of the tangent line in polar coordinates." ##7.##...
  22. JulienB

    Calculating Work with Line Integrals: Solving a Force Field Problem

    Homework Statement Hi everybody! I would like to make sure I properly solved that problem because I find the result strange: Given a force field ##F_x = axy^3##, ##F_y = bx^2y^2##, ##F_z = cz^3##. Calculate the work with the line integral ##\int_{C} \vec{F} \cdot d\vec{r}## from point...
  23. Alistair McCheyne

    Drive line inertia and torsional effects exam question

    Hi can anyone help me with this question on inertial forces in gears? Cheers Ali :)
  24. G

    Location of bend line on sheet metal flat layout?

    For a flat layout sheet metal part, is the bend line located directly in the middle of the bend allowance section, or is it inset from one side by a distance of the bend radius? So for a U-channel with an opening of approx. 4.56" (distance between inside of legs), would the distance between the...
  25. S

    How Do You Calculate Work Done in a Vector Field Along a Parametric Path?

    Fine the word done in moving a particle in the force field F=<2sin(x)cos(x), 0, 2z> along the path r=<t,t,t2>, 0≤t≤π To do the line integral, I need to find F(r(t)), but I don't understand how to express it. For example I looked at the online notes provided here...
  26. terryds

    What is the value of c when the areas above and below the line y = c are equal?

    Homework Statement In the picture above, line y = c intersects with parabola y = 6x-x^2 in the first quadrant. If the gray area below line y = c and the gray area above line y=c are equal, then value of c is ... A. 19/4 B.21/4 C.23/4 D.25/4 E. 27/4 Homework Equations Area under parabola =...
  27. prashant singh

    B Can we say that a line is a particular case of a triangle

    I think we can say that a straight line is a triangle in which sum of two side equals third side in which two angle equals 0° and the middle angle equals 180°, but can we say that a striaght line is a triangle with two angle equals 90°, I am saying this because my sister is not beliving that...
  28. malaxtom

    Particle dynamics applied to geometrically parametric line

    I have an odd, yet intriguing question. I want to describe a particle that is constrained to move along a straight line in the x direction. The location of the particle can be described with theoretically infinite parametric parameters, d, along the line. For example: R = [d 0 0]T R = [d2 0 0]T...
  29. S

    Line integral over a vector field

    Homework Statement Evaluate ∫C < −y, x − 1 > dr where C is the closed piecewise continuous curve formed by the line segment joining the point A(− √ 2, √ 2) to the point B( √ 2, − √ 2) followed by the arch of the circle of radius 2, centered at the origin, from B to A. 2. The attempt at a...
  30. Kyrie

    I Finding the equation of a bitangent line to a curve

    The curve y=x^4-2x^3-2x^2-2x has a bitangent. I need to find the equation of this line. First, I started off by computing the slope. Since it touches two points on the curve, their slopes should be the same. So, I have the equation 4x^3_1-6x^2_1-4x_1-2=4x^3_2-6x^2_2-4x_2-2 I got up to the point...
  31. super_adun

    I K-beta line for the X-ray spectra of Molybdenum with Moseley

    This should be easy but I'm totally stuck here. So I'm calculating the Kβ line (emitted energy) of Molybdenum (Mo 42). I'm using Moseley's law and am moving from the M-shell to the K-shell. Recall Moseley's law is E = 13.6 eV (Z-σ)2 *1/n2. The effective formula for the energy emitted is thus...
  32. P

    Finding an electric field at a point from a line of charge

    Homework Statement A thin insulating rod with charge density lambda=+5nC/m is arranged inside a thin conducting cylindrical shell of radius r =3 cm. The rod and the shell are on the same axis, and infinite in length. What is electric field at point p? 6cm from the central axis. Homework...
  33. Kirito123

    Identifying the slope of a line

    Homework Statement identifying the slope of the line?[/B] Homework Equations y2-y1/x2-x1 The Attempt at a Solution i chose two points on the line, the first point is (8,-3) and the second point is (-6,4). Are these points accurate? i used the slope equation to solve for the slope of the line...
  34. Kirito123

    Im trying to determine the y and x intercepts of this line.

    Homework Statement I am trying to determine the x- and y-intercepts of the line 3x – 5y + 15 = 0. Homework Equations standard form The Attempt at a Solution :[/B] To find the x-intercept (where the line crosses the x-axis), substitute 0 in for y: 3x + 5y + 15 = 0 (substituted 0 in for y)...
  35. Kirito123

    Determining the equation of a line

    Question: Determine the equation of a line for the following: a) The line that has an x-intercept of 6 and that passes through the point (2, –2) b)The line that never intersects 5x – y + 3 = 0, and which is five grid squares lower than that line Relevant equation: y= mx+b Attempt at a...
  36. S

    Electric Field along bisector of charged line (w/error)

    Homework Statement You wish to determine the electric field magnitude along the perpendicular bisector of a 230-mm line along which35 nC of charge is distributed uniformly. You want to get by with a minimal amount of work, so you need to know when it is sufficient to approximate the line of...
  37. Destroxia

    Calculating Surface Area Using a Line Integral: A Case Study

    Homework Statement Use a line integral to find the area of the surface that extends upward from the semicircle ##y=\sqrt{9-x^2}## in the ##xy##-plane to the surface ##z=3x^4y## Homework Equations Parametric Equation for Circle: ## x = rcos(t) ## ## y = rsin(t) ## Line Integral: ## \int_c...
  38. M

    I Dispersion relation of a transmission line - questions

    Hi, I have transmission line with dispersion relation ω=sin(kx), so then means that for one value of ω I have two values of k. I apply voltage with some frequency with is allowed to move in the line. First question is, how can I influence what k will be generated inside the line. The another...
  39. prashant singh

    I Why Are Longitudinal Lines Perpendicular to the Equator?

    I think its a defination to have infinite longitudnal lines , if line are not perpendicular than the infinite point will not add up to give the circumferance of equator, please help
  40. I

    MHB Angle between two line segments of a cube.

    Given a cube, choose a vertice and draw 2 of the three possible diagonals. What is the measure of the angel between those two diagonals? Proposed answer: We can say that both diagonals touch vertice A, to give it a name. We can also call the endpoints of both diagonals B and C. If we imagine...
  41. skate_nerd

    How to make thick line error bar for plot

    Disclaimer: I'm not exactly sure that this topic would belong in this thread but I don't think it would fit better anywhere else. I'm working on writing a paper for my grad research project and my PI wants me to model the plots after another paper that our lab published in the past, but I'm...
  42. S

    Line Integrals: What Do They Represent and How Can They Be Visualized?

    Homework Statement Need to visualize what it means by Line Integral along curve C with respect to x or y axis. For example suppose the curve is C (I did not find a way to write the C under the integration sign here) ∫ f(x,y) ds is like a fence along C whose height varies as per f(x,y). The...
  43. gsmtiger18

    Line charge creating induced emf and displacement current

    Homework Statement A long, straight wire has a line charge, λ, that varies in time according to: λ = λ0 exp(-βt). A square wire loop of dimension a is located adjacent to the wire at a distance of a from the wire. Calculate expressions for the displacement current at the center of the wire loop...
  44. B

    MHB Parametric representation of a line

    I am give the following curve r(t) = (t+1,0.5(1-t),0) where t ranges from -1 to 1. I am now trying to derive a new parametric representation of this line segment using the arc length as the parametric variable. I have integrated r'(t) from -1 to 1 and found that the length of the segment ranges...
  45. Derek Francis

    Professors: Where's the line between opinion and bias?

    With social science courses, there's lots of opinions and perspectives. I think it's inevitable that the professor will lean one way or another, and I don't think having an opinion is bad insofar as you're overall fair about the class. One professor I knew taught in Introduction to Global...
  46. A

    Fortran How to run command line scripts from within Fortran 90

    Hey! I'm currently making a program which is a three body problem. I managed to get working results which I can plot to gnuplot. The question is, how can I write this within the program itself, so it can automatically plot the information to gnuplot if the user wants it to? (I'm being lazy :P)...
  47. F

    Hydraulic grade line (HGL) vs energy line (EL)

    Homework Statement i was told that the major loss causes EL and HGl to decrease gradually , while minor loss causes EL and HGL to decreses rapidly ... Why ? Homework EquationsThe Attempt at a Solution is it because the minor loss(energy loss-( which is caused by the friction loss in the bent...
  48. C

    Ideal Straight Line - instrumentation HND

    Homework Statement I am doing a distance HND and need to find the ideal straight line of a sensor output. The sensor is a temperature sensor with an OHM output. From a temperature range of 0-250 it has an output of 120-364ohm. temp output 0 = 120 50 =...
  49. phosgene

    Comparing SD of data with RMSE of regression line

    Homework Statement I'm being asked to compare the standard deviation of a data set with the root mean square error of the regression line used to model the data, in order to determine the reliability of the regression line. Homework Equations Mean squared error = variance + bias squared The...
  50. Wi_N

    Transformation T as a projection on a Line

    Homework Statement T: R^2 --> R^2 given as a projection on the line L = 5x+2y=0 decide matris T? Homework EquationsThe Attempt at a Solution L= 5,2 X=x1, x2 projL on X = (5x1+2x2)/29 *(5,2) = 1/29 [25 10 10 4] is this correct?
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