Center Definition and 1000 Threads

Sorry if this is posted in the wrong section I'm trying to find out what would be a good pick point on a steel point instead of just winging it. There are two sections to the steel pole, both combined together to create a total of 78 feet. The first section is 40' and weighs 3,438.004...

[PLAIN]http://www.link-systems.com/sdkhtml/SDK/print/pr9849.gif

Homework Statement A uniformly charged insulating rod of length 14.0 cm is bent into the shape of a semicircle. The rod has a total charge of -7.50\muC. Find (a) the magnitude and (b) the direction of the electric field at O, the center of the semicircle. Homework Equations...

Homework Statement Homework Equations Please see attachment to #3. The Attempt at a Solution Apparently, the answer is Y= 4R/(3*pi). Why?

Homework Statement A binary star system consists of a star P and a star Q, of mass 4.0 x 10^10 kg and 2.0 x 10^10 kg respectively, separated 6.3 x 10^9 m apart. Star P and Star Q move in circular orbits with their centers at the center of mass which remains at rest. Find the position of...

Given 2 points on a circle, call them A and B. I know the cartesian coordinates of A. I also know the radius of the circle, the slope of the tangent line at A, and the length and direction of the arc between A and B. I don't know the coordiates of the center of the circle. How do I find...

I was thinking that objects like a sphere have a center of mass in the middle of the sphere and also if you were in the middle of the sphere you would feel no gravitational pull in any direction. So then I was wondering if all objects had a zero gravitational pull at their center of mass. But...

Hello All, I am trying to create an experiment to determine the center of mass and inertia tensor of an aribtrary object. This object is small (softball size), and non symmetrical on all axis. I have some thoughts concerning gyroscopes and accelorameters, but am curious to see what thoughts...

Homework Statement So I have a triangle with points: A (4,2,0), B (3,3,0), and C (1,1,3). We are to find the point at which the three medians intersect in i,j,k format. I've found the midpoints of each side but I don't know where to go from there.

As part of a problem I need to find the center of mass of a hollow hemisphere. I did it in the following way. I considered the lower hemisphere ( around negative z axis ) First by definition, the position vector of the center of mass is obtained as \vec{R}=...

http://helios.augustana.edu/~dr/203/probs/Set%201.pdf Scroll down to #11 for a picture. So I kind of understand the math. I am a little confuse though. So why is a divided by sqrt(2)? If this is a vector, then the center is really (a(sqrt(2)))/2 and the x component would be divided by...

Homework Statement A large wedge rests on a horizontal frictionless surface. A block starts from rest and slides down the inclined surface of the wedge, which is rough. During the motion of the block, the center of mass of the block and wedge. a. does not move. b. moves horizontally with...

Homework Statement Calculate the electric field (magnitude & direction) at the center of a square 52.5 cm on a side if one corner is occupied by a = -38.6 µC charge and the other three are occupied by -27.8 µC charges. Homework Equations Enet= E1center + E2center + E3center + E4center...

Homework Statement Design a full-wave regulated power supply using a 5:1 center-tapped transformer and a 7.5 V, 1 W Zener diode. The power supply must provide a constant 7.5 V to a load varying from 120 to 450 . The input voltage is 120 V(rms), 60HZ.Homework Equations The Attempt at a Solution...

Homework Statement The mass of the homogeneous flat plate is 50 kg. Determine the reactions at the supports A and B. I've attached the diagram. The Attempt at a Solution I know I will need to find the center of mass. I don't remember exactly how to do it, but I found the centroid...

i think it should but I am not sure.

"Infinity" at the Center of the Galaxy http://www.sciencedaily.com/releases/2011/07/110719151234.htm http://www.wired.com/wiredscience/2011/07/milky-way-ribbon/ New observations from the Herschel Space Observatory show a bizarre, twisted ring of dense gas at the center of our Milky Way...

Calculating the direction of the "center" of the universe? I've had a theory lingering in my consciousness for a long time. I've wondered about the relevance between the speed of light, red-shift in stars and galaxies and relativity. Although c is a constant, I have read somewhere that...

Am studying electrical engineering, i was wondering about how to initiate research and development in engineering field, and how to select and find the ideas that will be studied and solved. Suppose a study is done, for whom this new technology will be sold and who will save your rights...

Chris McKay told me that they do take grad students, but I can't find any more information on the Internet (the Ames page points to a dead link for the "Graduate Student Researchers Program") - see http://hr.arc.nasa.gov/student/gradfaculty.html

Homework Statement A 1.0 kg rock is suspended by a massless string from one end of a 1.0 m long measuring stick. What is the mass of the measuring stick if it is balanced by a support at the 0.25 m mark? Homework Equations Torque=(distance perpendicular to force from the center of...

This is a pretty tough question for me. I am trying to learn, so please no rude people or trolls please. Here is the problem I was given. A 50 dyne steel rod is fixed at a point 20cm. from the right end. The clamp at this point provides a force of 200 dynes upward. The rod is in equilibrium...

uniformly distributed load on a beam. it has a single simple support at the center of gravity. Beam length L and load distribution w (pounds/inch) How do I find the shear and moment diagrams?

Homework Statement Two identical uniform rectangular flat planks with sides a and b are glued together to form a T-shaped object. Specify the position of the center of mass. State any theorems you use in order to arrive at your conclusion. See the attempted solution for a diagram. :) The...

I have a project to do and I have to make a demonstration about a physics phenomenon. I'n planning on doing a demonstration that explains one or all of Newton's Laws of Motion. I've chosen to do it on the center of gravity, but I want to know if it's related to Newton's 3 Laws of Motion or is it...

As the title. More specifically, with respect to the center of momentum frames massless particles don't have, why not if they still do have relativistic mass? (Bracing for an easy answer to a stupid question...) :redface:

Homework Statement so we have this engineering assignment (high school final year) where we have to design an airplane wing and one of the tasks is to (graphically, not all of us can even differentiate let alone mathematically derive it) identify the center of mass of the wing... now, i know...

I am wondering about the size of the universe. I have read that we can only "see" 13.7 billion light years away in all directions and that we are in the center. To my mind this presents a problem. The problem is what are the odds that we are in the center of the universe? Then again even...

In Boas' book I can read that the definition of center of mass of a body has coordinates x_{CM}= \int x_{CM}dM= \int x dM. Shouldn't it be this same integral but divided by M?! Also, I didn't find the definition of center of mass for particles or any non continuous bodies. I'd be grateful if...

Homework Statement In a plastic film factory, a wide belt of thin plastic material is traveling between two successive rollers with the speed v. In the manufacturing process, the film has accumulated a uniform surface electric charge density σ. What is B near the surface of the belt in...

hey. I used to be quite talented at math, but I've let my talent deteriorate in the ~10 years since my last calculus class. I have a problem which I'm sure I would have devoured easily back in my school days, but am having trouble with now. I am considering two points on a normal (0 to...

Homework Statement 2 stars are separated by a distancce r, one star has mass 2/3M the other has mass 2M (M is a solar mass). The period of revolution is 5 years, calculate r. Homework Equations Fg=(GM1M2)/r^2 The Attempt at a Solution Ok so I know that the binary star...

Hi there, so I'm a bit confused...I'm 14 years old and I'm living in Croatia.I heard for Hallow Earth theory one year ago so I wanted to research it, but I had no material i needed until today...data(material9 i needed is what is radius of Earth on poles and Equator and what g is there...

I'm studying the chapter 'Steady State Cornering', from the book 'Fundamentals of Vehicle Dynamics' (by Gillespie). The concept of a 'roll center' seems to be very important here, especially after the 'roll axis' is defined (line joining the front and rear roll centers). But I don't...

Hello, i need help on this question, i have been thinking about it assume there is a hole through the center of the Earth , and oxygen is exist so we can breath , if we drop the ball into the hold, is it possible for ball go through the center of the Earth to other side of the hole ? so what i...

Homework Statement Calculate the center of gravity of this object: http://img638.imageshack.us/img638/8412/inddddd.jpg The Attempt at a Solution The bottom line turns out zero, so I get something over zero therefor error! http://img101.imageshack.us/img101/6995/theretherere.jpg

Either the Big Bang began in a small, restricted area/volume/domain/node/etc or the universe sprang into existence "everywhere all at once" -whatever that means- as I once read somewhere (to explain why the universe has no center). So which is it? And if it sprang into existence in a homogenous...

Hi, I have 4 non-planar points P1 = ( x1 , y1 , z1 ) P2 = ( x2 , y2 , z2 ) P3 = ( x3 , y3 , z3 ) P4 = ( x4 , y4 , z4 ) what is the coordinate of center of mass of the object ( tetrahedron ) whose vertices are P1 P2 P3 and P4? ( uniform density ) Thanks

From some reason Yc's result is different than mine. But, the solution manual and me are using the same X axis to calculate Yc (we're using a different Y axis to calculate Xc, though). Can someone explain to me what's wrong here?[SIZE="4"]The question: [SIZE="4"]Calculate the center of mass of...

Hello everyone, I will begin by saying if this question is a repeat, I am sorry. I searched and only found similar questions but not any discussion on this specific point. With that that: Consider an ideal model of Earth: uniform density, spherical, solid mass. The classic question...

Homework Statement Given potential r=2m on the surface of the sphere which meets the Laplasian equation (triangle)u=0 and is u(2,theta,psi)=5sin(theta)sin(0.25psi). I need to find the potential of sphere center. Can anyone help me? Homework Equations ? The Attempt at a Solution ?

Hi, I'm wondering how to calculate the center of pressure for a rocket. More precisely, i know that the C P is located on the axis of the nozzle but i don't know how to located it on this axis... With FLUENT and a 3d simulation, Fluent can't located it (Fluent gives me 2 differents...

If you place a charge +q at the exact center of a conducting sphere, will it stay there or move to the surface?

Could anyone help me figure out a formula to calculate a Center of mass for a non uniform object. In my case it would be a "shell" that would go over a body of a solar car. If anyone could help me that would be great.

I understand we can calculate that gravitation is neutralized at the center of a mass - say, a planet or star (or anywhere within a spherical shell); I wondered if the GRS is also neutralized, or if being pervaded by gravity - however neutralized - the dilation of space-time persists therein.

Homework Statement Or any coordinates really. In the normal Cartesian plane, the center of mass is defined from the x, y , and z distance as follows \bar{x} = \frac{1}{Area(R)}\iint_R x dA \bar{y} = \frac{1}{Area(R)}\iint_R y dA \bar{z} = \frac{1}{Area(R)}\iint_R z dA Now is there one for...

Homework Statement A metal rod is 50cm long. Its linear density at the point x cm from the left end is given by the equation p(x)=1/(100-x) gm/cm. Find the mass and center of mass for the rod. Homework Equations mass = \int p(x)dx center of mass = moment / mass The Attempt at a...

Center of mass of ... I just don't know where to post this...feel free to move it. Assuming our universe is the 3-dimensional surface of a 4-dimensional sphere, my question is: where is the center of mass of the universe ? Nowhere, everywhere, is it in the center of the sphere ? There's no...

The South Carolina House of Representatives yesterday rejected a bill which would have granted amazon.com an exemption from collecting SC sales tax on purchases from SC residents. In response, amazon.com has stopped construction of a new distribution center near Columbia which would have created...