Axis Definition and 895 Threads

Homework Statement A rigid body is made of three identical rods, each with length L = 0.525 m, fastened together in the form of a letter H, as in Figure 10-56 below. 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...

Hi, 1) Do we calculate torque with respect to a point or with respect to an axis? I have read them both in different resources, and so I am confused! 2) If we calculate torque with respect to an axis, many introductory textbooks discuss the motion of the gyroscope by considering how the...

Homework Statement Charge is uniformly distributed along the x-axis with density ß. Use Gauss' Law to find the electric field it produces, and use this to calculate the work done on a charge Q that moves along the y-axis from y = a to y = b. Homework Equations...

Homework Statement consider the following rotation matrix: 0 0 1 1 0 0 0 1 0 Find the axis of rotation. Homework Equations The Attempt at a Solution I know the following: Ω|1> = |2> Ω|2> = |3> Ω|3> = |1> where Ω is an operator. It is a cyclic permutation. What do not understand is...

Homework Statement Problem in the attachment Homework Equations -r(dθ/dt)^2= Centripetal force F=ma The Attempt at a Solution The tension force will be cut into two parts. I split the distance between the two strings into two sections, so the distance "r" to the mass can be...

An ellipse is represented by \rho(t)^2=x^2(t) + y^2(t) where \rho(t) is the distance from origin to the ellipse at a given time. The way the article used to find the major and minor axis is the take the derivative \frac{d(\rho^2(t))}{d t}=0 to find the maximum and minimum. My question is why...

Since the redistribution of mass in the Earth's surface can be caused by earthquakes, sometimes the Earth's rotation is increased or decreased by a small amount. Recent series of quakes seem to be related. To me, this makes sense, since if plate "A" should move, then plate "B" would also...

Homework Statement http://img687.imageshack.us/img687/8767/meprob27.jpg If the resultant force acts along the positive u axis, determine the resultant force and angle theta (red angle) Homework Equations law of sines pythagorean theorem, etc trig parallelogram, head to tail methods...

Okay this has been bothering me, I know what the x-axis on sine graph mean, but not the y axis. I know when I type for example: sin(pi) I will get 1. But what is that 1? I know its the y cordnate. But what is it?

I was wondering if someone could have a look at my attempt at calculating the resultant vector of 3 forces. Figure is here:http://tinypic.com/view.php?pic=2psrllz&s=6, and from the top down the forces are F1=24,9kN, F2=12,7kN and F3=21kN. The angles are(again from the top down) 56,4°, 15,3° and...

Homework Statement I've been reading through Spacetime Physics by Taylor & Wheeler, but this argument about the invariance of the y coordinate for inertial frames, one moving relative to the other on the x axis, is tripping me up. I'll just write the text word for word: I'm just not...

Hello! I couldn't find any answer to a wondering I have: On one end of a light string, attach a heavy ball, and on the other end of the string hold it with your hand and whirl around the ball-on-string. You reach a high rotational speed and finally the string breaks at the string-ball...

\vec E\;=\; \hat x E_{x0}\cos(\omega {t} -kz)\;+\;\hat y E_{y0}\cos(\omega{t}-kz+\delta) For z=0, this is a vector that trace out an ellipse with time t. I want to 1) to verify that using the definition of differential calculus, we can find the length of the major and minor axis by...

I read that if the cone with apex angle 2α whose central axis is vertical, apex at the origin, then one can use spherical coordinate to calculate the solid angle of the cone ∫02∏∫0αsin\varphid\thetad\varphi However, what if the central axis is align to y-axis horizontally, instead of...

Why do we have x-axis perpendicular to y-axis? Why not 45° or something else? Even if we keep any other angle other than 90° we can still build up all other vectors using them in the plane. So what is there is 90° that makes it special and simpler?

I have a quick question. On a typical cartesian coordinate system you have the x-axis and y-axis for two dimensions and the z-axis for the third. What would you label the axis representing the fourth dimension? I know this is a bit of a silly and unimportant question, but I was thinking...

Homework Statement Find the volume generated by revolving the regions bounded by the given curves about the x-axis. Use indicated method in each case. Question 11: y = x^3, y = 8, x = 0 Question 15: x = 4y - y^2 - 3, x = 0 Homework Equations for question 11: Shells for Question 15...

I am a High School student and I was told that magnetic field appears whenever you align the electrons around the atoms (when they spin in the same direction around their axes). Is this true or do schools actually mislead people?

Homework Statement Find the volume of the solid generated by revolving the region between the parabola x = y^2 + 1 and the line x = 3 about the line x = 3. Homework Equations The answer is found by integrating with respect to y with disk method, but I don't understand why my answer is...

Homework Statement THE ANSWER IS CHomework Equations None given. Pondering: E=(1/(2(pi)εnaught))(σ/z^3) p=qd U=-p dotprod EThe Attempt at a Solution We have attempted many variations of the above equations to try and find the answer. We are just seeking a point in the right direction as we...

Griffiths brings up a point that it might make sense that current in a fat wire would want to concentrate itself mainly along the axis of the wire, given that parallel wires attract each other. He then asks us to figure out why this might not happen, but to be honest I would think it should...

Hi I have a question on how to work with quantization axis. The setup I am looking at is a single two-level atom placed at the origin (0, 0, 0), which is not perturbed by any magnetic field. I now send in a laser resonant with the transition of the atom. With a right-handed coordinate...

If you have a solenoid positioned along the z axis... ...how would one find the b-field at slight deviations of x and y? I have been googling for hours and can't find anything other than the fact that it is very difficult! Thanks guys!

Homework Statement I have to find reaction at the joints but that's not important. I'm having trouble understanding what the book is doing but first allow me to explain the diagram so there is no confusion because 3D pictures are kinda hard to draw. In the first diagram there is a crank shaft...

I have two 3d applications and when an object(a cube for example) is transferred between them, the rotation values of the cube change(the object stay at the same location. translation and scale values stay the same) and I can't find why that occurs and it's driving me crazy. app 1 rotation...

Homework Statement [refer to picture, thanks] The "L-shaped" figure rotates on the axis which which intercepts through 9 kilogram and 2.5 kilogram masses. Find the moment of inertia of the object for this type of rotation. Disregard the masses of connecting bars. Homework Equations MR^2...

Homework Statement A current flows in vertical square coil whose plane is at right angles to a horizontal uniform magnetic field B. The coil can rotate about a vertical axis. Which is correct A) The forces on the two vertical sides are equal and opposite. B) A couple acts on the coil C) No...

I think I heard long ago that the redshift of all parts of the surface of a spinning star as seen from a distant point on the axis is expected to be the same, at least in theory, because of the following argument. Please can anyone confirm or refute this? A body which is capable of being...

Any python/matplotlib experts out there?? This one has been driving me crazy all day. I have three vectors, azimuth, frequency and power, which I would like to histogram and plot on a polar axis. I can plot a scatter plot this way no problem but the histogram gets messed up somehow. An example...

I don't have a good grasp of "spin along axis" topic, so pardon my dumb questions: 1. Does a photon/electron have a different spin across each of the 3 axis? i understand that the spin of an electron/photon is not the same as that of, say, a ball 2. Gravity can distort time-space (and hence...

Object rotation about a fixed axis?? question about derivatives in this problem?? An object rotates about a fixed axis, and the angular position of a reference line on the object is given by θ=0.40e^(2t), where θ is in radians and t is in seconds. Consider a point on the object that is 4.0 cm...

Homework Statement The chair is 10 m from the rotating vertical axis. The solid overhang stretches 6 meters from the axis. (making 4 m from end of overhang to chair on the radial axis). The chair spins at a constant speed at 1 revolution per 10 seconds. Find the angle θ the cable makes with...

Homework Statement Rotate the region bound by the given curve by about the x and y axis. Find the volume through the cylindrical method. x^2 + (y-1)^2 = 1 Homework Equations Cylindrical method: ∫2∏xf(x)dx Slice Method: ∫A(x)dx The Attempt at a Solution x^2 + (y-1)^2 = 1 x =...

Hi, I need to do this for some homework and I don't really understand... could anyone help with the following question: Find the area of the pentagon PQRST with vertices P = (1,1,1), Q = (5,−3,1), R = (9, −1, −5), S = (2, 6, −5), T = (1, 2, 0). Hint: divide the pentagon into triangles...

just curious if anyone knows where there is online graphing program that will graph trig function with radians on the x axis tried Wolfframapha but not thanks ahead

Homework Statement about what point and about what kind of axis can we conserve angular momentum?can we conserve it about a point moving in circular motion? Homework Equations The Attempt at a Solution its just a understanding based question to apply to problems

Homework Statement Calculate by direct integration the moment of inertia for a thin rod of mass M and length L about an axis located distance d from one end.Homework Equations I = Ʃmir2i Which can be rewritten as int (r2)dm as Δm -> 0 Since we cannot integrate over a mass, we need to switch...

Homework Statement if a disc of mas m is pure rolling , with velocity v . the instantaneous axis of rotation would be the point of contact with the ground . As shown in the diagram this could be considered as a disc rotating about one of the point on circumference for an instant of time ...

Homework Statement y = {\frac{1}{4+x^2}} on the interval [0,2], revolving about y = -1 Use either the disk/washer or shell method to find the volume. Homework Equations v = pi\int (outer radius)^2-(inner radius)^2\,dx v = 2pi\int (radius)(height)\,dy x = \sqrt{\frac{1}{y}-4}...

Hi, this isn't really a homework problem... but I'm just wondering I see the time axis as c*t, now people say that its to scale the time axis so that the world line of light is 45 degrees. But if you were to multiply time by the speed of light, wouldn't you just get the units metres or...

Hello, Can some explain to me how to calculate the power coefficient of a vertical axis wind turbine. If you explain the steps invloved would be great or any external file location where I could refer. I have below information 1) Lift Coefficient. 2) Drag Coefficient. 3) Angle of...

I can easily visualize the 3 dimensional way to do so, and already have. I'd like to rotate from the (-1,-1,-1,-1) -- (1,1,1,1) line to the x-axis (-1,0,0,0) -- (1,0,0,0). To do so in 3 dimensions (-1,-1,-1) -- (1,1,1) line to the x-axis (-1,0,0) -- (1,0,0) I rotated around the z...

1. Deriving the major and minor axis of an ellipse from conjugate diameters pointsCurrent solution: double x1 = Diameter1.X - Center.X; double y1 = Diameter1.Y - Center.Y; double x2 = Diameter2.X - Center.X; double y2 = Diameter2.Y - Center.Y; double xc = (x2 + y1) / 2; double yc = (y2 - x1) /...

1. Homework Statement http://session.masteringengineering...bs._454_55.jpg Find the moment about the axis AC. F=<7,12,-6> 2. Homework Equations MomentAC = Uac dotted with (Rab X F) Uac is the unit vector from a to c 3. The Attempt at a Solution Uac=<.8,.6,0> Rab=<4,3,-2>...

Homework Statement http://session.masteringengineering.com/problemAsset/1127287/7/Probs._454_55.jpg Find the moment about the axis AC. F=<7,12,-6> Homework Equations MomentAC = Uac dotted with (Rab X F) Uac is the unit vector from a to c The Attempt at a Solution Uac=<.8,.6,0>...

Consider a freely rotating body. Let the axis of rotation be the z-axis. For simplicity assume all the mass of the body is concentrated in the x-y-plane, i.e. the plane in which the body rotates. I have read about the moment of inertia tensor on wikipedia, but I don't see how I would combine...

Says Wikipedia: "The moment of inertia is a measure of an object's resistance to any change in its state of rotation". Now consider a rotating mass m that I would like to accelerate along its axis of rotation by a. Does this count as a "change in its state of motion"? Will it resist the...

Hi i have cylinder geometry . bottom (cross section)circle centre point is x1, y1, z1 and top is x2, yz, z2. cylinder centre axis is not allign with any (Global x,y,z) axis. if i want to align a cylinder with Global axis(x,y,z), what is angle need to rotated with respect to x ,y ,z (Global )axis.

Homework Statement Determine the magnitude of the moment of the force F about the axis CA of the tripod ABCD, if F = {40i -30j -100k}N. Image attached. 2. The attempt at a solution Based on a similar question I found in the textbook my method to solve this question: Find UCA =...

A 180 degree circular arc (i.e. a half sphere) is obvious: When you rotate this about its two end points, you get a sphere. What about for something less than 180 degrees (e.g. 90)?: I believe this forms an ellipsoid, with coefficients a and b being equal, with respect to...