Axis Definition and 895 Threads

Ok, I have to make a 3D model of a figure bounded by y=4 and y=x^2 that is rotated about the x-axis. I believe it will form an hour glass shape and I am putting two half spheres together to form the model, is this right?

Hi everyone, I've got stuck on this prove problem:cry: Please help me! Let S be a rectangular sheet with sides a and b and uniform density, and total mass M. (a) Show that the moment of inertia of S about an axis L that is perpendicular to S, meeting S through its center, is I...

I heard that the recent Chile earthquake moved Earth's axis by 8cm or so. Could the Chicxulub asteroid (or the even bigger, Antarctic one I just http://www.dailygalaxy.com/my_weblog/2010/03/did-the-planets-most-massive-asteroid-impact-ever-occur-in-antarctica-nasa-gravity-maps-point-to-yes.html"...

Hi I am new to this forum and I am not even studying physics nor currently taking any classes in my old age. But I had a thought last night whilst tossing in my sleep and the question arose to my mind about what it would be like if I went to the North Pole and stood dead center aligned exactly...

In Einstein's 1905 paper he says that, by reasons of symmetry, we can assume the coordinate axis of the stationary and moving frame are aligned. If the y and z axis rotate towards/away from the x-axis in the moving frame in a way dependent upon the velocity, how does this break the symmetry...

Homework Statement I have a problem where the graph of the equation is below the x-axis at x=0, crosses the x-axis at x=2, and is above at x=5. To find the area of this would I just split the interval into two parts, find both areas, and then add them? Or would I simply ignore the part of the...

I have to plot the period t² vs the length but now i am confused which goes on the x-axis and which goes to the y axis, i was wondering if someone could help me out with this issue

Assuming that I have a C-Channel When the load acts along the X-X axis, we take Iyy for the Bending moment calculations. Similarly, when load acts along the Y-Y axis, we take Ixx. But if i have a load that acts on Z-Z axis, how do I calculate the Moment of Inertia? PLS SEE THE ATTACHMENTS...

Why do I get a different answer with the parallel axis theorem? [Solved] Homework Statement Imagine four points masses m1 = m3 = 3kg and m2 = m4 = 4 kg. They lie in the xy plane with m1 at the origin, m3 at (0, 2), m2 at (2, 2), and m4 and (2, 0). Each unit on the coordinate plane...

I have this equation for the magnetic field strength of an electromagnet but it’s in the form of multiple polynomials. Here is the page where they all are: http://www.netdenizen.com/emagnet/offaxis/solenoidoffaxis.htm since it gives values for e_8 and p_8 I tried using the main equation up...

Homework Statement Determine the magnetic field strength and direction at a point 'z' on the axis of the centre of a semi-circular current loop of radius R.Homework Equations Biot Savart Formula d\vec{B}=\frac{\mu_{0}Id\vec{r}\times\hat{e}}{4\pi|\vec{R}-\vec{r}|^{2}} e being the unit vector...

Hi, The area e^x-1 Is rotated about the y axis, bounded by y=1, x=0 and x=ln2 find the volume of the solid. And i am clearly making something wrong, so if anyone could verify my work. ~ 2\pi\int_0^{ln2}x\cdot(1-(e^x-1) -2\pi\int_0^{ln2}xe^x-2x Integration: u=x, du=1 dv=e^x, v=e^x...

If the Earth's axis were tilted at 45 degrees, would the sun ever rise on Christmas day in Winnipeg, Manitoba Canada? What I think: I think you would be able to see the sun rise if you look 7 degrees to the south since Manitoba is at 52 degrees but I'm not sure..

Reports being aired in the press about the Earth's axis having moved. Well I think its a load of codswallop. but the press is reporting this as if its real. For such an event to occur would mean that all the stars would have moved in relation to the Earth by a small amount, which means every...

Homework Statement Two children ride on a Merry-go-round. One is 2 m from the axis of rotation and the other is 4m from it. Which child has the larger; I. linear speed II. acceleration III. angular speed and IV. angular displacement Homework Equations 1) Linear Speed: v =...

The question is to find the acceleration of a certain section of a velocity-time graph, state its acceleration, if its speeding up or slowing down, and to state if its going north or south. (It states North = Positive) I was fine answering all of the questions until it went under the x axis...

I'm trying to make a bar graph from data which were taken at irregular intervals over 100m. I want the x-axis to be scaled instead of showing each data point one after another. (i.e. I'm coming out with 1-4-5 when I want 1-----4-5). I hope this makes sense - I'm not sure of the proper...

Homework Statement A uniform line charge of linear charge density 5 nC/m extends from x = 0 m to x = 4 m. Find the electric field at x = 7 m. Answer in units of N/C. Homework Equations 8.85 × 10^−12 C2/(N · m^2) is the permittivity constant 8.98755 ×10^9 (N · m^2)/C^2 is Coulomb's...

Two positive point charges each have a charge of +q and are fixed on the y-axis at y = +a and y = -a. (Use k, q, a, and x as necessary.) (a) Find the electric potential at any point on the x axis. V = 2kq/[sqrt(x^2+a^2)] (b) Use your result in part (a) to find the electric field at any...

Problem: a) 2 charges are located on the y-axis at positions +2 m (-2 microC) and -2 m (-1 microC) respectively. No other charges are present. Each grid is 1 meter. Compute the x and y components of the electric field at the point indicated at the position x = +2 m. Give 2 answers, Ex and Ey...

Homework Statement I need to find the volume of the solid generated by revolving this region bounded by the curves about the x-axis. y = sqrt(x), x+y=6, y=1 Homework Equations The Attempt at a Solution I find the intersections of these curves I get: (1,1), (4,2)...

I am a little confused about a histogram of force measurements. I was asked for my physics lab to state what the vertical axis and horizontal axis represent for a histogram of force measurements? the physics lab consists of pulling a wooden block with a force sensor to record the tension...

Can anyone confirm the Earth's spin axis direction with respect to the AXIS of rotation of the galactic center? (in this current epoch). I'm getting something like 84 degrees difference (6 degrees off perpendicular); Is that correct? If not tell me your method. Thx, Creator

Hi all. I am a recent Chemical Engineering graduate, and I recently was program recommended into the Naval Nuclear Engineering Program. While going over a study guide for my technical interviews coming up, I came across this problem, and my mind went blank! It goes something like this: 1...

Homework Statement Find the area under y = 6x3 - 2 for 5 <_ x <_ 10 Homework Equations The Attempt at a Solution I'm not sure how it wants us to do it; do we use sigma notation or the general right/left-hand sums? Using sigma notation, delta T = 10-5/n T0= 5/n (?) T1= 10/n Ti = 5i/n...

Homework Statement Two 2.04 µC point charges are located on the x axis. One is at x = 1.02 m, and the other is at x = -1.02 m. Determine the electric field on the y-axis at y = 0.470 m. Homework Equations E = k*q/r^2 The Attempt at a Solution First I find the distance from one...

Homework Statement Studying the mirage, we can assume that the index of refraction depends only on the vertical coordinate z. A ray of light starts from {0,0} with angle \beta\leq30. It's trajectory fits on an ellipse with major axis a and minor axis b. a) Give n(z)=? b) What is the trajectory...

Hi all. i am integrating in MATLAB and plotting the results in a y-vertical and x-horizontal system. where x and y symbolize j and i of a table. I have to re-label the y-axis, so instead of a 0 to 100, it should be 100-0. Is it possible to do that or does anyone have any idea or has any...

Hello :) Does an artificial satellite rotate in its own axis? tia

I want to figure out the 'a' of an ellipse (i.e. (major axis)/2) by knowledge of it's circumference and length of minor axis. Using my little knowledge which I gained from reading (roughly) the ellipse article of wikipedia; I realized that I need to use that notorious and approximate...

Hi, I'm doing a project in medicine, I've used MATLAB to create 3d graphs using a vector with 5 fixed values as X, a vector with 7 fixed values as Y. As Z I have 5*7 measured values. I need to interpolate my graph to "smoothen" the lines in the graph, but I am totaly lost, I have no idea how...

Can anyone suggest how to calculate the semi major axis of a body in an elliptical orbit when all I've got is x,y,z,vx,vy and vz? I'm guessing I need to calculate the eccentricity too. I really suck at conversions like this. :(

So I'm in the middle of a calculus 3 course, and one thing I've been lightly chewing on is how to change the direction of evaluation of a double/triple integral when the bounds are complicated enough that they can't be drawn easily on a graph. Would you have to use the optimization in several...

Homework Statement Consider a planet with uniform mass density p. If the planet rotates too fast, it will fly apart. Show that the minimum period of rotation is given by T^2 = 3(pie)/Gp Homework Equations F = ma = Gm1m2/R^2 (Equation 1) a = v^2/R (Equation 2) v= 2(pie)R/T...

Why are Horizontal Axis Wind Turbines used more often than vertical axis when it looks like a vertical axis has more of an advantage? Please can you explain it simply?

Homework Statement A wheel spins at 45rpm with its spin axis vertical. After spinning 15 sec, it is spinning at 60rpm with its axis horizontal. Find its average angular acceleration and the angle the avg acceleration vector makes with the horizontal.Homework Equations Sorry, I can't really do...

What is the instantaneous axis of rotation? Can you give some examples and a few situations in helping me understand this better. I can across this term while doing a problem in my physics textbook and I did not understand what it meant.

Homework Statement I must calculate the magnetic field for any point P on an axis passing through the middle of a square wire loop (whose radius is a and current is I). The situation is such that the square wire is on a plane that is perpendicular to the axis in which I must calculate the...

Homework Statement A rod is placed between two smooth perpendicular walls such that each end of the rod touches a wall. The rod is released with the bottom end making an angle @ with the horizontal (ground). Using the concept of instantaneous axis of rotation find the following: (a) The...

1. Thehttp://nft01.nuk.edu.tw/lib/exam/97/master/97ap-master.pdf" statement, all variables and given/known data A solid, uniform disk of mass M and radius R is oscillating about an axis through P. The axis is perpendicular to the plane of the disk. Suppose the friction at P can be ignored. The...

Greetings everyone, been having some problems with this question, A uniform circular disk has radius 36 cm and mass 350 g and its center is at the origin. Then a circular hole of radius 7.2 cm is cut out of it. The center of the hole is a distance 10.8 cm from the center of the disk. Find the...

Homework Statement Prove parallel axis theorem (Steiner's theorem). Homework Equations I_{parallel axis} = I_{cm} + Mr^2 The Attempt at a Solution I know Wolfram's site which seems to use http://scienceworld.wolfram.com/physics/ParallelAxisTheorem.html" I am not sure whether the hint of...

Homework Statement given z =y3 revolved around the y-axis what is the equation of the surface and then graph. Homework Equations The Attempt at a Solution I have no idea how to approach this, i tried searching around the net but nothing came out. pls help.

Homework Statement I'm having issues with this section in calc. I'm not at all sure what I'm doing! Here is the problem I'm having trouble with: Directions: Find the volume of the solids. Problem: The base of the solid is the disk X^2 + Y^2 <= 1. The cross-sections by planes...

Unfortunately my geometry is a little rusty: if I have an area A(x,y), and rotate it around axis z (yielding a symmetrical, circular body), what is the algorithm to calculate volume? Or am I remembering incorrectly, and the algorithms were for very specific shapes? E.g. a circular cylinder...

Homework Statement Compute the semimajor axes "a" of Halley's Comet. Given: orbital eccentricity e = 0.9673 period P =76 days (2.39674E9 seconds) Gravitational Constant G = 6.67428E-11 solar mass M = 1.9891E30 Kg. Also used in equations are: L = angular momentum of center of mass...

Two point-charges of +8 nC and -17 nC lie on the x-axis at points x = 0 and x = +10 m, respectively. Find the electric field on the axis at point x = +5.0 m. Assume vacuum. Answer in N/C. E= k0(q./r^2) Ok, this should be pretty simple, but for some reason it's not. First, I converted the...

Homework Statement How does the slope and y-intercept change if you reverse the x and y-axis of a linear graph. Will the graph still be linear? The original y=mx+b format followed the physics equation: V^2 = 2a(d) + Vi^2 Therefore, when y was "V^2" while x was "d", the y-intercept was Vi^2...

I've looked for this subject but perhaps I'm asking the question the wrong way. Please advise. Is there an extension of magnetic field (flux) beyond the beam axis of a laser? In other words, can one detect (or has anypone attempted to detect) the magnetic field around the a light beam in a...

Does it correspond with the centroid of the transformed section? For example, if a wood beam had a steel plate fixed along the bottom, would the neutral axis be lower than that of a pure wood beam of similar cross section? Any links showing example probs would be nice too. Sorry that this is...