Axis Definition and 895 Threads

Dear all, i met a problem that i couldn't get the on axis field of a finite solenoid that integrating from a thin shell solenoid equation. The thin shell equation link: http://www.netdenizen.com/emagnet/solenoids/thinsolenoid.htm And the on axis finite solenoid equation link...

Hello, I have a question regarding fft's. My experience with working with Fourier transforms is pretty much limited to transforming contrived functions pen and paper style. But now I need something and I think the fft is the appropriate tool, but I'm having a hard time understanding some...

Hi, this is my first post here, so please forgive any errors in my post. :) I'm recently thinking about switching from my major of computer science to physics, and have been brushing up on the first few semesters of physics I had taken a few years ago. I'm currently in the section on...

y=1/x, y=0, x=1,x=1, rotate around y axis; curious how to set this up using washers

Please explain what an "axis of inertia" or "principle axis of inertia" is! I have confronted these terms in a paper about molecular quantum mechanics, and they are completely unfamiliar to me. Can someone help?

Hi, I've been doing rotational mechanics at school and at the end of the chapter,the parallel and perpendicular axis theorems appear to have sprung out of nowhere! The proofs are given in the book but somehow, they don't make any sense. I can't understand their implications in the real...

Homework Statement A vector is given by R(vector) = 1.90 ihat + 1.30 jhat + 2.92 khat. Find the magnitude of the vector Find the angle between the vector and the x, y, and z axis Homework Equations I have read something about dot product but I am not sure if it applies here The Attempt...

Imagine we have a Equilateral triangle in the xy plane with one vertex at the origin. The triangle will be rotated about the z axis. The depth of the triangle, d, will be constant.B_r=B(r) From the picture I see that B_r=\frac{r}{h}B , V=\frac{B_rhd}{2}=\frac{Bdr}{2} First, I need to find...

i have two optical lens assemblies performing separate functions individually. Now I want to allign their optical axis .. how do i achieve the alignment? (actually i want to allign them back to back and ensure that their optical axes are concordant, if not overlaping ,then atleast parallel )

Calc. Angle between radius vector point and positive x axis? What does that mean? Homework Statement The cartesian coordinates of a point in the xy plane are x = −8.96 m, y = −1.75 m. Calculate the angle  between the radius- vector of the point and the positive x axis (measured...

The question that really troubles me is how fast the Earth spins around its axis? I was wondering that if the Earth spins really fast then why are the days slow.

Homework Statement Two particles, each with mass m = 0.85 kg, are fastened to each other, and to a rotation axis at O, by two thin rods, each with length d = 5.6 cm and mass M = 1.2 kg. The combination rotates around the rotation axis with angular speed w = 0.30 rad/s. Measured about O, what...

Homework Statement While the bridge is closing with a constant rotation of .5 rad/s, a man runs along the roadway such that when d=10ft, he is running outward from the center at 5 ft/s with an acceleration of 2 ft/s^2, both measured relative to the roadway. Determine his velocity and...

given the following system: 2 cords are attached to point C, http://picasaweb.google.com/devanlevin/DropBox?authkey=Gv1sRgCL_4l4PpvP_YsQE&pli=1&gsessionid=oBksCECRwcHSRoX-oRPaRA#5329455433140212770 and knowing that |TCB|=380N |TCA|=450N find: 1) the moment relative to x,y,z 2) the...

[FONT="Arial Black"][SIZE="4"]Hello physicists I have a circular body goes around its axis very fast. I am seaching for answer for these questions 1- How can I calculate its momentum or the energy that it has? 2- What is the forces that limit its motion? please I need your help thanks a lot

when i saw how to get the electic potential of a charged disk at a point on its axis i found that the E.P on center of the disk =0 as the integration of the eq: dv = 2k(q/a^2)((r^2)+(x^2))^(.5)dr...(a) is the radius of the disk , (r) is the radius of the element and (x) is the distance...

A small boat hangs from two brackets, one of which is shown in the figure. It is known that the moment, on the z axis, the resulting force Ra applied in the point A of support must not exceed the value of 217 N.m, in value absolute. Determine the more value possible the traction force in cable...

Homework Statement Find the potential at off-axis points due to a thin circular ring of radius a and mass M. Let R be the distance from the center of the ring to the field point and \theta be the angle between the line connection the center of the ring with the field point and the axis of...

Moment of inertia of a rod: axis not through the centre!? Homework Statement A meter stick of mass 0.44 kg rotates, in the horizontal plane, about a vertical axis passing through the 30 cm mark. What is the moment of inertia of the stick? (Treat it as a long uniform rod) Homework Equations...

Homework Statement A tightly wound solenoid of length L and radius a that has n turns of wire per unit length carries a current I. Calculate the the magnitude of the magnetic field at a point P on the axis of the solenoid, outside it and a distance y from one end, as shown in the figure...

Hey guys, A picture of the question is attached, I am not seeking answers just an explanation of some theory. Now I understand that point A will be under compression due to the weight, tension due to the bending and shear due to torque produced by the wind point b will be under compression...

Homework Statement The asteroid Pasachoff orbits the Sun with a period of 1417 days. What is the semimajor axis of its orbit? Determine from Kepler's third law, using Earth's orbital radius and period, respectively, as your units of distance and time. ans : _______ km Homework...

Homework Statement The electric potential at points in an xy plane is given by V = (2.7 V/m2)x2 -(4.4 V/m2)y2. What are (a) the magnitude of the electric field at the point (3.4 m, 1.6 m) and (b) the angle that the field there makes with the positive x direction.Homework Equations I have...

Very quick question: A uniform meter stick held by one end is swung in an arc and released when the person’s arm is horizontal, so that it moves initially away from the ground. About which point will it rotate as it flies before striking the ground? Is it the 50cm mark since once released...

(i)Show that the magnetic field \mathbf{B} on the axis of a circular current loop of radius a is \mathbf{B}=\frac{\mu_0 I a^2}{2(a^2+z^2)^{\frac{3}{2}}} \mathbf{\hat{z}} where I is the current and z is the distance along the x-axis from the centre of the loop. I've done this part...

Homework Statement A rigid body is made of three identical thin rods, each with length L=0.600m, fastened together in the form of a letter H. The body is free to rotate about a horizontal axis that runs along the length of one of the legs of the H. The body is allowed to fall from rest from...

ineed your help please ihave two stepper motors and iwant to used in two axis solar tracker but ihaving aproblem in the light sensor icant decided yet the pest kind of sensor,and there are need to use aposition sensor also in my plant.

Homework Statement Imagine a cylinder of radius R and Length L. Both of it's ends are open and it carries a uniform surface charge desnity of sigma (@) Find the electric potential at any point along the axis of the cylinder, and then use that to calculate the electric field at any point...

Homework Statement I have attached a figure showing beam bending around 2 axis. I need to calculate section modulus Sx and Sy but seem to be getting the major and minor axis confused. I guess the problem comes in when I go to select which term is squared in my equation below. Homework...

Homework Statement a) If Vx = 18.00 units and Vy = -15.50 units, determine the magnitude of V. b) Determine the angle of V with respect to the x-axis. Homework Equations The Attempt at a Solution Yeah, Part B is pretty much the only one I don't get . a) Answer is 23.75 b)...

Hello i need help to get this working if its possible, will try explain what i have come to. I have 2 dc motors that I want to control six different axes, if motor 1 spins right and motor 2 spins left then the first axle will rotate. if motor 1 spins left and motor 2 spins right then the...

Homework Statement A cylindrical rod 24.0 cm long with a mass of 1.20 kg and a radius of 1.50 cm has a ball with a diameter of 8.00 cm and a mass of 2.00 kg attached to one end. The arrangement is originally vertical and stationary, with the ball at the top. The apparatus is free to pivot...

Hello folks, I was wondering how to set up a volume of the solid of revolution about a line in the form of a line equation. if i wanted to find the volume about a line of x/4 would I simply find it as v=pi*integral (f(x/4)^2)dx or is there a method I'm missing all togeather?

Homework Statement I have a point p(xp,yp,zp) inside an ellipsoid and i want to find the angle of that point from the center of the ellipsoid(xc,yc,zc) . I also have the major axis length 'a' ,with length ax,ay and az components I calculated the unit vector of axis a with formula...

The Problem A projectile is thrown from a sloping hill with an initial speed of 20m/s directed perpendicular from the slope. If the incline of the slope is 32 degrees, how far from where it is thrown will the ball land? I found these equations will result in a solution... Want: R = square...

If a two dimensional object (say a circle) spins, their is a zero dimensional 'point' that stays in the same place as it spins. If a three dimensional object (sphere?) spins on its axis, there is a one dimensional 'line' (its axis) such that any part of that sphere that lies on that line...

Is the parallel axis theorem always valid for inertia tensors? We have only seen examples with flat (2d) objects and was wondering if it would also be valid for 3d objects, like a h emisphere, for example. Thanks.

Homework Statement I'm having difficluty in finding the second moment of area and neutral axis of this beam can anyone help Homework Equations The Attempt at a Solution I know that you have to divide the beam into two rectangles, I have used the formula bd3/12 and Izz, i did Izz...

The problem is very similar to #9.74, here: http://books.google.com/books?id=o4-5K8xqlY0C&pg=PA504&lpg=PA504&dq=product+of+inertia+L5+angle&source=web&ots=KMDPgSTiT9&sig=rYBjTLwd-bTiA-IrMRCXB5XNycs&hl=en&sa=X&oi=book_result&resnum=1&ct=result#PPA504,M1" I understand how the parallel axis...

Homework Statement Two particles, each with mass m=0.0036kg, are fastened to each other and to a rotation axis at P, by two thin rods, each with length L=0.68m and each with a mass of 0.0086kg. The combination rotates around the rotation axis with an angular velocity of 13.0rad/s. Find the...

Homework Statement A cone of mass M has a height h and a base diameter R. Find its moment of inertia about its axis of symmetry Homework Equations I=\int R^{2}dmThe Attempt at a Solution I tried starting by finding dm. It's equal to the mass per unit volume, \frac{M}{\frac{1}{3}\pi R^{2}h}...

Hi every body I have a bounce marks on a quistion that i know nothing about its about the Ellipse the Qustion is Find the standerd formula of the eelips which has foci on ( 1,1) and ( -1,-1) and it has a major axis with 4 units. i found that the center in at the origin...

curve ball problem, the spin axis will change?image updated! HI, I encountered a problem about the curve ball (table tennis ball) flying in the air. See the pictures below. A ball with an initial velocity V along X axis, and has a spin along Z axis. As far As I know ( see my previous...

The air drag and magnus pass through spin axis? A ball is flying in the air, and it has spin on y axis, show below. F1 is the air drag force. F2 is the magnus force. My question is: the air drag and the magnus force is pass through the spin axis? Or, the ball will change the torque...

Hello, can anyone explain to me what the moment of inertia is? we learned the mass moment, second moment and the first, and I'm getting confused as to what they all are. and can anyone explain what the strong/weak axis is? is it resistance to bending or rotation? i just can't visualize where the...

y = |x| can't go below the y-axis because a Modulus is always positive, but can you get a modulus that stops x going negitive? Could this be used for things like radioactive decay where the graph should go in -x but doesn't because you can't have - time?

1. I am considering the problem of getting the equation for a 3d vector(magnitude irrelevant) in cartesian coordinates when given 2 angles with respect to arbitrary axes. 2. I think that 180-angle1-angle2=angle3 3. So if the angle between the x-axis and the vector is 60deg, and the angle...

How are torques computed about an axis when the axis (and the attached body) are both accelerating at the same rate? For example, if a car is in free fall with the doors open (with the rear end of the car pointing towards the ground) will the doors shut themselves due to torque? Or, is the...

the solid lies between planes perpendicular to the x-axis at x=1 and x=-1 the cross-sections perpendicular to the x-axis are A) circles whose diameters stretch from the curve y = -1/squrt(1+x^2) to the curve y = 1/squrt(1+x^2) B)vertical squares whose base edges run from the curve y =...

Homework Statement Find the angle between the x-axis and the force F2, and the magnitude of the resultant force? Homework Equations The equation of the triangle: a(squared) = b(squared) + c(squared) - 2bc cos A The Attempt at a Solution What I did was that I said that since the...