Line Definition and 1000 Threads

  1. D

    Orbital atmosphere (Karman Line -1000km)

    The Earth Rotates at complete revolution at 24 hours, the troposphere and stratosphere are dragged along with it at the equator, but what about 100km-1000km above the equator? Is there a formula or chart that astronomers can use to predict the tiny amount of drag that satelites have to encounter...
  2. Monoxdifly

    MHB [ASK] A Line Intercepting A Circle

    A circle whose center is (2, 1) intercepts a line whose equation is 3x + 4y + 5 = 0 at point A and B. If the length of AB = 8, then the equation of the circle is ... A. x^2+y^2-24x-2y-20=0 B. x^2+y^2-24x-2y-4=0 C. x^2+y^2-12x-2y-11=0 D. x^2+y^2-4x-2y+1=0 E. x^2+y^2-4x-2y+4=0 I don't know how to...
  3. S

    B Can We Use Regression Line x on y if y is the Dependent Variable?

    I have note that states regression line x on y is used when we want to calculate x for given y but in this case y is dependent variable. I am pretty sure I can use either line if the value of product moment correlation coefficient (r) is close to 1 but for the case, let say r = 0.6, can we use...
  4. A

    I Maximum separation on an infinite line

    If the maximum separation between two points on an infinite line is finite, then what is its value? So the maximum separation is infinite. Does this mean two points on an infinite line can be separated by an infinite distance? Why, why not?
  5. kmot

    I Why is this closed line integral zero?

    This problem comes from fluid dynamics where Kelvin circulation theorem states, that if density "rho" is a function of only pressure "p", then closed line integral of grad(p) / rho(p) equals zero. It seems so trivial, so that no one ever gives reason for this claim. When trying to solve it...
  6. Poetria

    Equation for a line through an origin

    Why is this wrong? $$-4*y+x=0$$ $$\vec (-1, 4)\cdot\vec (4,1)=0$$
  7. petefa

    50Hz and 60Hz supply neutral line question

    Hi, I have a question, I think the answer is no you can't do it, but I want to know why. First mains supply - 3phase N + E (50hz) Connected to this first supply is an inverter that gives out a 3 phase 415vac @60hz (no neutral) second supply. The 60hz inverter output feeds 3 independent tapped...
  8. N

    How can I overcome the lack of support for my passion for mathematics?

    Slope of a Tangent Line For f (x) = x^2 − 1: Find the slope of the secant line containing the points P = (−1, f (−1)) and Q = (−1 + h, f (−1 + h)). Solution: I think I need to find f(-1). f(-1) = (-1)^2 - 1 f(-1) = 1 - 1 f(-1) = 0 Point P becomes (-1, 0). I now must find f(-1 + h)...
  9. S

    MHB Mechanics- General motion in a straight line.

    It's the second question. Limiting equilibrium by a force of 5N means even friction is acting in the same direction. I don't understand how to calculate. Pls help
  10. N

    Can you clarify your understanding for parts (a) and (b)?

    Slope of a Tangent Line For f (x) = x^3. (a) Find the slope of the secant line containing the points (2, 8) and (3, 27). (b) Find the slope of the secant line containing the points (2, 8) and (x, f (x)), where x does not equal 2. For (a), I just have to find m, the slope using m = delta...
  11. S

    MHB Mechanics- General motion in a straight line.

    Iam not able to get the ans for q(a) which is 6.5 m/s I don't understand how to calculate (b)
  12. S

    MHB General motion in a straight line

    I calculated (a) I don't know how to calculate (b)
  13. S

    MHB Mechanics- General motion in a straight line.

    A woman on a sledge moves in a straight line across horizontal ice. Her initial velocity is 2 m/s. Throughout the journey her acceleration is given by a= -0.01t m/s^2, where t is the time from the start in seconds. Find the distance that she travels before coming to rest. Iam getting the ans...
  14. S

    MHB Mechanics- General motion in a straight line.

    A goods train starts from rest at point A and moves along a straight track. The train moves with acceleration a m/s^2 at time t s, given by a=0.1t^2(6-t) for 0<t<6. It then moves at constant velocity for 6<t<156 before decelerating uniformly to stop at point B at t=165. Calculate the distance...
  15. S

    MHB Mechanics- General motion in a straight line.

    A particle starts at the origin and moves along the X- axis. The acceleration of the particle in the direction of the positive x-axis is a= 6t-c for some constant c. The particle is initially stationary and it is stationary again when it is at the point with x coordinate = -4. Find the value of...
  16. S

    MHB General motion in a straight line.

    In q(c) I calculated the distance using t= 4.25 S . I get S=-3.23×10^-3 I added 5.78m to this which is the distance between A and B, I get 5.78m. Is this the correct method to prove that the bird returns to A. Pls help
  17. S

    MHB Mechanics- general motion in a straight line.

    I don't understand q(e) . Am I not supposed to calculate the distance between the interval 0 to 2? The textbook ans only shows the interval between 0 and 22. Should I calculate the distance taming only the second equation of velocity?
  18. F

    I Calculate m (slope) of a line given the angle in degrees

    Hi, I want calculate the m = slope of a linear line WHEN I already know the angle in degrees of the line. Here is an example: I calculate with Excel the angle with the following function: =+DEGREES(ATAN(0.0874887)) and I get as result the angle of 5%. But how do I calculate the value...
  19. S

    MHB Mechanics- general motion in a straight line.

    A particle moves in a straight line. The velocity of the particle, v m/s, at time t s is given by v= -t^3+9t m/s for 0<t<5 a) Find the displacement of the particle from its original position, when t=5s I got the ans for this by integration and limits 5 and 0 =- 43.8 b) work out the distance...
  20. S

    MHB Mechanics- general motion in a straight line.

    I calculated q(a)=1s q(b)=7cm I don't understand q(c)
  21. S

    MHB Mechanics- general motion in a straight line.

    S for 0 to 2s = 20m From 2s to 2.5s, I integrated v with limits 2.5 and 2 and got s=8.875m So total distance would be 28.9m but the textbook ans is 29.9m. Iam not able to get 29.9 m
  22. L

    Transmission line with 2x termination

    Trying to work out the match for a transmission line with 2x termination. Like the one here: https://ibb.co/p4dY7pF V1=1 R1=R2=T1=T2=50, V1 sees R1 and T1. So it is divided to half. Now you have 0.5V source with a 50 Ohms series impedance(T1) looking into a load that is a parallel combo of...
  23. S

    MHB Mechanics- general motion in a straight line

    I don't understand how to find the distance that robot travels in 10s.
  24. S

    MHB Mechanics- general motion in a straight line

    I don't know how to calculate this. Pls help
  25. MikeandSuch

    Measuring the speed of light in a straight line

    So recently I watched a video detailing how it is impossible to measure the speed of light in a straight line because it's not possible to synchronize two-time measuring devices without first knowing the speed of light. But I was thinking if light can orbit a black hole in the photon sphere...
  26. Eclair_de_XII

    LaTeX How to loop through reading .txt files while conditioning on line no.?

    \newcommand{\printNum}[2]{% #1 #2% } \newread\readEng \newread\readEsp \newread\readLineNo \newcount\myLineCount \myLineCount=0 \newcommand{\printNumRow}{\loop\global\advance\myLineCount by 1\read\readEng to \Eng \read\readEsp to \Esp \printNum{\Eng}{\Esp}\ifnum\myLineCount=\linenum...
  27. H

    Rate of energy dissipated by a power transmission line

    VR = IR = 400 [ 29*10^-6 * 800 * 10^3 ] = 9280 P = IV = 400*9280 = 3.7 MW I was able to calculate the correct answer from the above, but why can't I use the equation P= V^2 / R?
  28. M

    MHB Least squares regression line (I'm very lost)

    Hi! Basically this is the exercise: Given the covariance of x and y is -12 and the variance of x is 6,5, using the least squares line of best fit connecting x and y yo estimate the value of x when y=15 x 2 5 9 7 9 10 7 y 25 17 11 10 8 7 13 any help would mean everything, I'm desperate :(
  29. GhostLoveScore

    Interferometer delay & line light spreading

    In every article that I've read about optical interferometers they explain that collimated light from farther the telescope is sent down the delay line, and then into a beam combiner with other beam. Like in the photo below But they all only show light that enters the telescope along the axis...
  30. J

    MHB Equation of a Line Completing System with 3x - 2y = 8

    Q: Write an equation of a line that forms a system with the equation 3x - 2y = 8 that has infinitely solutions. A: 3x - 2y = 8. I believe this to be correct because it makes an identical line to one of her correct answers (6x - 4y = 16) and nowhere did it specify that it had to be new. Could...
  31. P

    A Transmission Line in Accelerating Frame: Energy Conservation Puzzle

    While I believe I have an answer to this problem, I think it's an interesting one and counter-intuitive. I think it might spark some interesting discussions. The bow of a Born rigid accelerating spaceship has a proper acceleration of g. There is a transmission line running from the stern to...
  32. A

    MHB Circle a equation in a straight line

    how to circle a equation in a straight line y= 2x-1 y = x^2+ 2 x –y = 1 x = y + 5 y = – x^2 + 5 pls help me
  33. A

    How Does 5% Scattered Light Affect Equivalent Width?

    How much does the equivalent width of a line change by the introduction of 5% scattered light? We know the equivalent width is defined as We know the equivalent width is defined as $$W = \int_{-\infty}^{\infty} \bigg(\frac{1-F_{\nu}}{F_c}\bigg) \, d\nu$$ where ##F_{\nu}## represents the flux in...
  34. M

    Engineering Gas turbine (mean line) analysis question

    Hi, I was attempting another turbomachinery question and am struggling with a few concepts. The question is: "A single stage gas turbine for power generation is designed for the following overall duty: - Power output is 4.2 MW, and mass flow rate is 70 kg/s - Inlet stagnation pressure = 3 bar...
  35. icesalmon

    Engineering Lattice Diagram for Transmission Line

    The propagation speed of the wave is C/sqrt(9) = up if the length of the transmission line is 2m then every 10ns it will pass through the middle of the transmission line. But the switch in the circuit is opened after 5ns so after the current wave bounces off of the Load for the first time it...
  36. lambdajitsu

    A Lagrangian for straight line in XY-plane (dependent on time)

    https://dst-public.s3-us-west-2.amazonaws.com/lagrangian.png
  37. Username600

    Help with Creating An Excel Line Graph

    -------------------------------- Hi, just some backstory: My mom and my brother Rob, both loaned me some money in August 2020. They each loaned me $1000.00. I decided to use excel spreadsheet to keep track of my progress paying them both back. Okay so here is the data table I created; as you...
  38. PhysicsTest

    Line and Phase voltages differences

    When i study the 3 phase systems, this is want i understand for a Star connection Line voltage is ##\sqrt 3 V_\phi## and leads the phase voltage by 30Degrees. ----> eq1 So, from above we can conclude that both Line voltages and phase voltages are sine waves with phase difference. But in case of...
  39. karush

    MHB 311.1.5.19 parametric equation of the line through a parallel to b.

    $\tiny{311.1.5.19}$ find the parametric equation of the line through a parallel to b. $a=\left[\begin{array}{rr} -2\\0 \end{array}\right], \, b=\left[\begin{array}{rr} -5\\3 \end{array}\right]$ ok I know this like a line from 0,0 to -5,3 and $m=dfrac{-5}{3}$ so we could get line eq with point...
  40. R

    Power Line Losses: Trivial Problem, Confusing Answer

    This problem is trivial, but I cannot make sense of my answer (I am not even going to bother with the cost calculation. First, I used P=IV with P=15 MW and V=120 V to find I=125 kA So far so good. Then I calculated the resistance per meter as R=\rho\ell/A=(1.68\times 10^8\Omega\cdot...
  41. A

    How to solve an unclear geometry problem — Counting line segments in a rectangle

    120-48=72 72/4=18 The solution appears too simple to be the correct to me.
  42. Y

    C/C++ Understanding Inheritance and Polymorphism in C++

    Hi There is one line of code I don't understand and I cannot find it in the book: #include <iostream> #include <iomanip> using namespace std; class GradedActivity {protected: double score; // To hold the numeric score public: GradedActivity() { score = 0.0; }...
  43. karush

    MHB 311.1.5.14 Use vectors to describe this set as a line in R^4

    ok, just now looking at some examples of how to do this $x_4$ is just a row with all zeros
  44. Y

    A geometry question in Comsol (draw a semi-circle tangent to a line)

    I am new to Comsol. I want to draw my model which is a Tesla valve. The geometry is little complicated and I don't know how to draw a semi-circle tangent to a line. Is it possible? I draw it in Solidworks and imported it into Comsol but it gives error and I think it is better to draw inside...
  45. badluckmath

    Electric Field of two line charges

    I'm trying to solve this, but i don't really know how to start this problem. There are two line charges and i must find the E. Field on the center.
  46. J

    How Do Sign Conventions Affect Calculating Net Force on Charges?

    So 0=q1q3/r+q2q3/(13.6-r) 0=-8.5/r-3.63/13.6+3.63/r 0.2669=3.63/r-8.5/r r=-18.2465, but the answer is supposed to be 8.24
  47. S

    Line Integral to Verify the Magnetic Field B

    Hello folks, I'm working on a question as follows: I appreciate that there might be more sophisticated ways to do things, but I just want to check that my approach to the line integral is accurate. I will just give my working for the first side of the path. So I have set up the path as a...
  48. MarkNormand99

    Finding the gain coefficient at line centre for a HeNe Laser

    I have found the value for the full width at half maximum line profile width , I know the the density of the upper lasing state for the helium neon laser is 10^18 m−3, and I am assuming I have to use dN_2/dt = -A_21N_2, which I can turn into N_2(t)=N_2(t=0)exp(-A_21*t), and I have calculated...
  49. cwill53

    Pressurized Line and Rigid Tank Probem

    I'm stuck on part 1 at the moment. What I had so far was Using the ideal gas model, we have Solving these equations is reliant on the molar mass μ of the substance or the pressure p in the tank, which I don't know how to find with the given information. I sent an email to my professor and...
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