Axis Definition and 928 Threads

  1. karush

    MHB Find the area beween the curves y=x^2 and x+y=2 and the x axis

    Find the area beween the curves $y=x^2$ and $x+y=2$ and the x axis First on graphing these the $x-axis$ seem irrelevant in that it is outside the area to find. y=x^2;y=-x+2
  2. M

    Moment of force from an axis - 3D problem

    Homework Statement An OAB pipe is embedded in O. A cable BC = 1000N and F = ( 0,-f , 0) act on B. Question: Determine the magnitude of the force F as the resultant moment about the axis OA is canceled. Picture in attachment: Homework EquationsThe Attempt at a Solution O=(0 0 0) A=(1.5 0 0)...
  3. kostoglotov

    Gravity of a disk acting on a mass on the z axis

    Homework Statement A lamina has constant density \rho and takes the shape of a disk with center the origin and radius R. Use Newton's Law of Gravitation to show that the magnitude of the force of attraction that the lamina exerts on a body of mass m located at the point (0,0,d) on the positive...
  4. Tana-ami

    Discontinuous at horizontal axis, U and K points, in energy

    I have a question about horizontal axis of energy band. In band structure of FCC lattice, like Si, GaAs, the horizontal axis have discontinuous at U point and K point. But other region have continuous like from Gamma to X or to L. I cannot hit on an idea about this discontinuous. Would anyone...
  5. R

    Moment of inertia of rod about an axis inclined

    Homework Statement What is the Moment of inertia of rod about an axis inclined? It is given as ## \frac{ML^2sin^2θ}{12} ## but how? Homework Equations I know MOI for axis passing through center along y-axis as ## \frac{ML^2}{12} ## The Attempt at a Solution Shouldn't it be ## \frac{ML^2}{12}...
  6. B

    How Do You Calculate the Volume of a Rotating Body Around Different Axes?

    Homework Statement The curve y=1/x and the line y=2.5-x enclose an area together. Determine the exact volume of the rotating body that is formed when this field rotates about a) The x-axis and b) The y-axis Homework Equations The formula for rotation around the x-axis is pi*integrate from b to...
  7. C

    Potential of a point at the z axis of the circular ring?

    So i have a thin circular ring laying at the XoY plane, inner radius of the ring is a, outer is b, density of electricity is given by expression ρ=ρ0*b/r , where ρ0 is a constant and r ∈ (a,b). I have to find a potential of the point P with coordinates (0,0,z).I tried to do it two ways, but...
  8. R

    New coordinates from the rotation of an axis

    Homework Statement There is a point P(x,y) and now I rotate the x-y axis, say by θ degree. What will be the coordinates of P from this new axis. I have google but found formula for new coordinates when the points is rotated by θ degree. So I tried my own. So is there other simplified formula...
  9. Q

    A doubt respect to the sign of the torsor (torque)

    Homework Statement Actually I have two doubs, the first one is Why in the solution of this problem, in the sumatory of moments in C, Force 2=10?? If in the sumatory of moments in F, Force 2 is 416.7 N. Actually I calculate with 416.7 N, and T in C = 100 N. The other doubt is with the sign...
  10. Y

    How Fast Is the Large Hoop's Center Moving When Aligned Vertically?

    Homework Statement Two hoops are fastened together as shown below. Smaller hoop mass m, and larger hoop mass 3m. The system is now placed on the table and the system is released from rest in the position shown below. There is sufficient friction between the large hoop and the table so that it...
  11. CAH

    Does integration give area between graph and x axis?

    Does integrating find the area between the curve and x-axis (regarless of it being a smile/frown or any other graph)? I've heard people say its the area UNDER a curve... but then how would you even get a definit answer surely it may be infinite if there's no restrictions? Thanks
  12. H

    MATLAB Set Axis Font Size Independently in Matlab

    To set axis font size I use set(gca,'FontSize',20) but this command also acts on legend font size. How to set axis font size independently?
  13. P

    Surface Area of y=sin^2(x)+x^2 from 0 to 1 about x axis

    Homework Statement Set up a definite integral for the surface area generated by rotating the curve ##y= \sin^2x+x^2## from ##x=0## to ##x=1## about the a-axis. Homework Equations Surface Area about x axis=##2 \pi y \cdot ds ## The Attempt at a Solution I found ##\dfrac{dy}{dx} = 2 \sin x\cos...
  14. B

    Magnetic Field in plane 90 degrees off Helmholtz coil axis?

    In a recent Physics lab, I experimented with the magnetic field generated by two Helmholts coils. I used a Hall probe, and some software created by the Grad students to plot the field strength against probe position in a series of configurations. I understood almost all of the lab, I...
  15. C

    Neutral axis vs microstrain plot

    hi, i got a list of data containing strain for four different strain gauge, lb, and time elapsed. is there anyway i can calculate the distance from bottom of a girder using the given data to plot something like this? i have also been given the neutral axis for each strain gauge.
  16. Hugo S

    General Equation of the Line of the Major Axis of an Ellipse

    This is a question I have been playing with this week out of curiosity but I keep coming up against brick walls and unenlightening results. Given the equation of an ellipse, say $$ x^{2} - xy + y^2 = 2, $$ I would like to find the equation of the line which passes through the major axis. I...
  17. Tarpie

    How to Rotate a Surface Area about the Y-Axis?

    Greetings, y=x2/4 - ln(x)/2 from 1=<x<=2 rotated about the y-axis. I did the equation rotating about the x-axis via 2pi* integral (f(x)*sqrt(1+f'(x)^2)) dx with dy/dx = x/2 - 1/2x but the question calls for rotation about y and i can't seem to rearrange the equation to isolate for...
  18. C

    Find the probability of measuring spin up an axis.

    Homework Statement Set |Ψ> = (1/√ 2) | ↑, z> + (eiθ / √ 2) | ↓, z>. Find the probability of measuring the spin component of sz to be up the z-axis. Find the probability of measuring the spin component of sx to be up the x axis. Homework Equations I'm not sure. The Attempt at a Solution I...
  19. karush

    MHB Volume about x axis using cylindrical shells

    Use the method of cylindrical shells to find the volume of the solid obtained by rotating the region bounded by the given curves about the x axis. $x=1+{y}^{2}$, $x=0$, $y-1$, $y=2$ https://www.physicsforums.com/attachments/4237 The answer is $\frac{21\pi}{2}$ but I couldn't get it using...
  20. H

    Rotation matrix about an arbitrary axis

    Suppose a position vector v is rotated anticlockwise at an angle ##\theta## about an arbitrary axis pointing in the direction of a position vector p, what is the rotation matrix R such that Rv gives the position vector after the rotation? Suppose p = ##\begin{pmatrix}1\\1\\1\end{pmatrix}## and...
  21. A

    AXIS P1355 Camera I/O + relay to turn on light/garage door

    here is the manual http://www.axis.com/en/files/manuals/um_p1355_49956_en_1303.pdf see page 61 Notes: i have seen this thread https://www.physicsforums.com/threads/axis-camera-with-i-o-and-relay-to-turn-on-lights.538043/ but this camera is a bit different i think as it has digital inputs and...
  22. Chrono G. Xay

    Kinetic Energy of Double Compound Pendulum and Parallel Axis

    Kinetic Energy of Double Compound Pendulum and Parallel Axis Theorem Hello, there. I have a project I'm working on where I need to be able to calculate the kinetic energy of what basically amounts a double compound pendulum. However, the pivot point of the second pendulum is not at the center...
  23. C

    Equilibrium Question: Arbitrary Axis of Rotation?

    Ok, I solved the question posed in the attached image. I did so by using the car's center of mass as the location of my axis of rotation, generated torque and force equilibrium equations, and solved for all unknowns. When I try to use another location for my axis of rotation, e.g., the point...
  24. J

    MHB Proving elipsoide radius of axis i equals 1/sqrt(λi)

    Proving elipsoide radius of axis i equals 1/sqrt(λi) How is radius related to eigenvalues? I can't find the connection ... :S
  25. RicardoMP

    Gyrocompass motion: Zero torque in the free axis

    Hi! At the moment I'm studying rigid body motion, more specifically, the gyrocompass. As you can see in the attached picture (Introduction to Mechanics -Kleppner-Kolenkow-Chap.7), the gyrocompass rotates about the z axis and the spin angular momentum is reoriented towards the z axis, creating a...
  26. JesseJC

    Moment of Inertia about an axis at the center of mass

    Homework Statement 3.) What is the moment of inertia of the object about an axis at the center of mass of the object? (Note: the center of mass can be calculated to be located at a point halfway between the center of the sphere and the left edge of the sphere.)...
  27. A

    Direction of instantaneous axis in rigid body dynamics

    The general motion of a rigid body can be considered to be a combination of (i) a motion of its centre of mass about an axis, and (ii) its motion about an instantaneous axis passing through the centre of mass. These axes need not be stationary. Consider, for example, a thin uniform disc welded...
  28. Joseph Nechleba

    Potential along the X Axis due to Charge Distribution?

    I have a question regarding electric potential and infinity. So, "A square of side length a with uniformly distributed positive charge lies on the yz plane with its center at the origin. What does the graph of the potential along the x-axis look like? The answer given in the textbook is a...
  29. N

    Finding the Axis of Symmetry in a Parabola: How to Solve the Problem

    Homework Statement The Attempt at a Solution I would guess it is -b/2a but I have gotten this incorrect. Maybe I have to figure out what the parabola equation is and apply it into the axis of symmetry. Assuming that is correct how would I find that? Thanks[/B]
  30. H

    Precession of Earth's axis and alignment with stars

    I picked up a book about the pyramids at Cheops. (Relax, it wasn't a crackpot work.) It said that the pyramid was aligned with the star Polaris, and that Sirus and Orion may be sighted through some of the ventilation shafts. Now the pyramid is aligned with true north. It the time of the...
  31. J

    Improper integrals: singularity on REAL axis (complex variab

    Hello everyone! I'm having some troubles when I try to solve improper integrals exercises that have singularities on the real axis. I have made a lot of exercises where singularities are inside a semicircle in the upper half side, but I don't know how to solve them when the singularities are on...
  32. J

    Find First Place Where F <= 0 in O(log n) Time

    Homework Statement Consider a strictly decreasing function F: ℕ → ℤ. We want to find the "first place where f is at or below the horizontal axis." Assume we can compute ƒ(i) for any input i in constant time. Clearly, we can solve the problem in O(n) time by evaluating ƒ(1), ƒ(2), ƒ(3)...
  33. T

    Can Numbers Only be Graphed Using the Z Axis and What are They Called?

    If I understand correctly an imaginary number can be graphically shown in a x/y axis graph. Are there numbers that can only be graphed by using the third z axis? What are they called? tex
  34. M

    Moment of inertia of a rod at an angle to the axis

    suppose a uniform rod of mass M and length L is at an angle B to the x axis, one end of the the rod touching the axis. wish to find moment of inertia about x axis. let the rod touches the axis at x=0. let D=density=M/L, and I will integrate along x axis, that means that at a distance x from the...
  35. K

    Shape of a Bending Beam with P Applied at the Axis of Symmetry

    Homework Statement A beam (e.g. a steel liner) of a length L is bent between two supports, as shown in fig (a). According to the Euler column, the shape is a half period of a sine. Now, a force P is applied at the axis of symmetry - fig (b). What is the shape of the liner? y=f(x) Instead of the...
  36. B

    Adding Another Time Axis to Space-Time Diagram

    Can we add another time axis to Einsteins space time diagram? Since space and time are one thing they can be represented by one axis. The other axis can be a cosmological constant average axis. By adding this extra term can mass and energy be measured by a time scale relative to the expanding...
  37. Z

    Parabola incoming ray not parallel to axis

    If incoming light to a parabola is parallel to the central axis the light is reflected through the focal point and the back to its source. What about light coming in not parallel to the central axis. What path do these rays take?
  38. T

    Magnetic field of bent wire for a point along parallel axis

    Homework Statement Long wire is bent such that it forms two parallel line segments that goes to -∞ along the z-axis and a semicircle of radius (R). Find magnetic field on Z axis. Homework Equations Biot-Savart Law (μ0/4π) I = ∫ dl' x R/ R^2 where dl' is element of length and R is the unit...
  39. Fosheimdet

    Analyticity of the complex logarithm on the negative real axis

    A theorem in my textbook states the following: For every n=0,±1, ±2, --- the formula ln z=Ln z ± 2nπi defines a function, which is analytic, except at 0 and on the negative real axis, and has the derivative (ln z)'=1/z. I don't understand why the logarithm isn't analytic for negative real...
  40. Aristotle

    What is the definition of the D-Offset in the Parallel Axis Theorem?

    Homework Statement My question is, to gain more knowledge on, is in Physics, what is the terminology for D-offset in the Parallel axis theorem? Homework Equations I= Icm + Md^2 The Attempt at a Solution From my understanding, the offset is the distance away from the axis of rotation.
  41. Z

    Surface Function of Tilted & Rotated Circle Around Z-Axis

    My first idea is this will result in a elliptic torus. The horizontal semi-axis a=R and the vertical semi-axis b=R*cos(beta). assuming the titled or inclined angle is beta. The distance away from the z-axisis c and it is a constant. But it looks not when I plot the surface in 3D using the...
  42. K

    The electric field on the axis of a charged disk

    Homework Statement A disk of radius 10 [cm] is charged with 5E-9 [Coulon]. where on it's axis is the greatest electric field. Homework Equations The field on the axis of a charged disk: ##E=\frac{1}{4\pi\varepsilon_0}\frac{q\cdot \cos\alpha}{s^2}## The Attempt at a Solution I express...
  43. L

    The moment of inertia of a rod that is rotating off the end of the rod.

    Is there a formula for the moment of inertia? A thin, uniform density rod is rotating about an axis that is off the end of the rod, so it looks a bit like this: ------- | (------- is the rod and | is the axis of rotation, so the rod is rotating out of the plane of your screen) I just have...
  44. A

    Determining the magnetic field on the axis of a uniformly magnetized cylinder

    Homework Statement A cylindrical volume of length L, radius a, is given a uniform magnetization M along its axis (call it the z axis). The question is to first find the bound currents, then use them to find the magnetic field B, as well as "the auxiliary field" H - but only along the axis of...
  45. V

    Kinetic energy of a disk that turn around 2 axis

    I would like to know if kinetics energy of a disk with radius 'r', mass 'm' which turn around itself at Wb (relative rotation) and which turn around blue axis at distance 'd' is : 1/2md²Wa²+1/2mr²(Wa−Wb)² ? With Wa > Wb Look at image please.
  46. B

    How to shift the function xe^x mathematically by one unit on the x axis?

    Hi Folks, I have a function x {e^{-x}} and if i shift it one unit to the right on the x-axis we have (x-1) {e^{-(x-1)}} How do I show this mathematically? Even consider the simple case of x^2, if we shift by 1 unit to the right it becomes (x-1)^2 What is the method mathematically? Regards
  47. Drakkith

    Converting 2 Axis Input to an Angle

    I'm dabbling in video game creation and I'm making a very basic top-down twin stick shooter. The problem is that I don't know how to get the player to turn to an angle that matches the controller's right stick. I'm trying to figure out an equation or something to convert the -100 to +100 input...
  48. T

    Moments of inertia using parallel axis theorem

    Homework Statement The mass of a homogenous thin plate is 36kg. Determine it moment of inertia about the x axis Homework Equations Parallel axis theorem: Ix = Ix' + d^2*m The Attempt at a Solution p = m/a = 36/0.36 = 100 Because the density is homogenous, I found the mass of the first...
  49. D

    Does the Solar System spin around an axis and if so where is it?

    Hi, Does the solar system spin around an axis as it travels through space, much like a planet rotates as it orbits the sun and if it does where is the axis point. I know the solar system is orbiting the centre of the galaxy, I was just wondering if it behaved like a planet because things tend...
  50. C

    Lorentz transformation independence of axis orthogonal to velocity

    Apriori -- before taking any of the postulates of special relativity into account -- we might say that the lorentz transformations between two frames K and K', where K' is moving w. speed v along the x-axis of K, is given by $$\vec{x}' = F(\vec x, t)$$ and $$t' = G(\vec x, t).$$ Now, i want...
Back
Top