3d Definition and 1000 Threads

How to determine the bond angle based on the formula of molecules?

Dear all, I am looking for an interactive software that can let me play with 3d geometry. I apologize, as I am not sure of the right technical term of the sorts of shapes I am interested to work with. I am not a mathematician or physicist, but rather use these as philosophical metaphors and...

:confused: HI, is wave behaviour on a two dimensional field or in a multidimensional field in space?? i am currently conducting a study whether the object producing the wave is actually spinning and the resultant disturbance on the field it is residing causes the field to respond to the...

Hello, First time posting to Physics Forums. I have been thinking about rotation transformations and am a bit confused on how trig works in 3D. In 2D, convention says the positive x-axis points to the right, the positive y-axis points upward, and positive angles are measured from the...

Hi ll, I am currently working on 3d in xna. i have ismple collision detcetion working but I want to do triangle by triangle collision detection.How would I get a models base triangles? I have this adapted from online to fit in with my game: public struct TriangleVertex {...

Hello everyone ,i have captured car positons at differents frames.http://www.imagesup.net/pt-7140205392313.png%5D%5BIMG%5Dhttp://www.imagesup.net/dt-7140205392313.png Suppose car's(left side car which is coming towards us) centroid is at video frame1 is P(x1,y1) and Q(x2,y2) at video frame4...

If given three points ##P_0 = (x_0, y_0)##, ##P_1 = (x_1, y_1)## and ##P_2 = (x_2, y_2)##, the polynomial function ##f(x)## that intersect those points is ##f(x) = a_2 x^2 + a_1 x^1 + a_0 x^0##. where: ## \begin{bmatrix} a_0\\ a_1\\ a_2\\ \end{bmatrix} = \begin{bmatrix} x_0^0 &...

I'm a third year physics undergraduate and I want to make 3D Graphene - without spending a fortune. This is my background: I found this review article by Jiang and Fan (Design of advanced porous graphene materials: from graphene nanomesh to 3D architectures) to be very helpful. From what...

Hello, I've been using mathematica the past few days and quite like it. I am trying to add some figures to my word document. Because of the size of the exported emf file from mathematica, I am unwilling to have a document that is 100MB in size. So I was searching for some ways to export...

Hi, I am trying to resolve a force into xyz components and I think I'm getting a bit confused. When viewed face on the force is 35 degrees from the horizontal. When viewed from above the force is at 12 degrees from the horizontal (not sure if one would refer to it as the horizontal but see...

Homework Statement A particle is constrained by walls that form a cubic box. Obtain the wavecuntions and the energies. Homework Equations This is a summary of the solutions: http://quantummechanics.ucsd.edu/ph130a/130_notes/node202.html Here there is also some info...

Homework Statement Consider a 3D gas of N non-interacting fermions in a volume V at temperature T << Ef / k. Suppose that the particles in the energy range [0.25 Ef, 0.5 Ef] are suddenly removed. Calculate the Fermi energy of the remaining particles after the system reaches its new thermal...

Hello! I'm trying to model my truss with FEM using only beam elements in ANSYS, but I am experiencing difficulties with the constraints between the members (or coupling of the DOFs). For instance, I want my truss chords to be continuous and my lattice members to be pinned to them. I couple...

Looking at the image from this wikipedia article, it looks like there's a selective fluorescing of the quinine dependent on the presence of chrolide ions in the solution. If the concentration of chloride ions in a solution could be controlled into a particular shape, shining a violet laser on...

Homework Statement The rod assembly shown has a ball-and-socket joint at A and a smooth journal bearing at C. The forces F1=600N , F2=410N , F3=460N , and F4=950N are applied as shown in the figure. The geometry of the rod assembly is given as a=0.900m , b=0.650m , and c=0.800m...

So my professor said that the Kinetic energy of the particle in a 3D infinite well is dependent on position where in a 1D infinite well it's NOT dependent on position. She is sort of notorious for being wrong apparently and many of my undergrads are telling me she is wrong. I understand that...

I guess this question can apply in all the generality of the 3D Schrodinger eqn. with a central force, the case I'm thinking of however is the the hydrogen atom. When solving the equation, we derive the quantization of the angular momentum, which has me thinking that before we begin quantizing...

I'm developing a scanner that uses a laser for edge detection. It will be mounted on a hexacopter that will traverse a short distance through a cave/tunnel system and produce a 3D image. I'm still researching on ways to process this data but I'm thinking of using a edge detection algorithm in...

Homework Statement Calculate the single particle density of states for massless particles with dispersion E=h_bar ck for a 3D cube of volume V Homework Equations E=pc, p=E/c, dp=dE/c, d^3p = 4pi*p^2 dp k=sqrt(k_x^2+k_y^2+k_z^2) k_j = 2pi/L l_j (j=x,y,z) The Attempt at a Solution I...

I have created a contour plot in MATLAB using the following code: >> NP=40; >> [RP TP]=meshgrid(linspace(min(RPM),max(RPM),NP),linspace(min(BMEP),max(BMEP),NP)); >> BSFC_IT=griddata(RPM,BMEP,BSFC,RP,TP); >> NC=12; >> Fig1=figure; >> [CT...

One plane is flying due east straight and level at 30000 feet and at 420 mi/h. A second plane flies due north at 40560 feet and at 480 mi/h. The second plane crosses above the flight path of the first plane 2 minutes after the first plane passes that point. How fast were they approaching each...

Hello, I want to simulate a coil of a transformer in Maxwell (3D), but my problem is: the coil design is not a closed path. Imagine that you draw a ring and then you cut part of it. You get something like a "letter C". In these two terminals I`m going to put an excitation (100A, for...

Homework Statement I found this in Binney's text, pg 154 where he described the radial probability density ##P_{(r)} \propto r^2 u_L## Homework Equations The Attempt at a Solution Isn't the radial probability density simply the square of the normalized wavefunction...

Well when I watch movies I see space time as 2d. But how do we see the space time from Earth to a region lower than earth.

Homework Statement (See pic attachment)Homework Equations Moment/Torque = Force * d (Force arm)The Attempt at a Solution I have so far Mx = Fz * ya My = Fx * za Mz = -Fx * ya How I got these answers is by looking at the cube from the component's axis and whether or not it produces a torque...

Homework Statement The special-purpoise milling cutter is subjected to the force of 1040 N and a couple of 211 N·m as shown. Determine the moment of this system about point O. (Let's laugh at the text's typo)Homework Equations Mo = R x F + (Couple)The Attempt at a Solution I'm having a little...

Hi All, Greetings! I have a 3d material and I use result from first principal for getting the potential (U(x,y,z)). I then find average U(x) from U(x,y,z). Now if I write one dimensional Hamiltonian in X direction and use this value of U(x), can I get bandgap of the original 3d material (I...

[b]1. Homework Statement [/ In 3-D coordinate space, any two of the coordinate angles must … Select one: a. sum to less than 1 b. be greater than 90° but less than 180° c. each be greater than 45° d. sum to greater than 90° (if they are both less than 90°). e. have cosines less than...

Homework Statement In 3d coordinate space any two of the coordinate angles must A. Sum to less than one B. Be greater than ninety but less than one eighty. C. Each be greater than forty five degrees D. Sum to greater than 90 ( if they are both less than 90) E. Have cosines less than...

Homework Statement In 3D space a full vector can be represented I. All the following except A. In Cartesian vector form B.As a magnitude times a unit vector C. As a Cartesian vector times a unit vector D. As magnitude with coordinate angles Homework Equations The Attempt at a...

Hello everyone, First of all, I want to excuse for my not perfect English since it isn't my mother tongue. However, now to my problem, which I'm facing at the moment. As part of my master thesis I have to simulate the application of a fastening device, which I develope during my master...

Hello, I am looking to solve the 3D equation in spherical coordinates \nabla \cdot \vec{J} = 0 using the Ohm's law \vec{J} = \sigma \cdot (\vec{E} + \vec{U} \times \vec{B}) where \sigma is a given 3x3 nonsymmetric conductivity matrix and U,B are given vector fields. I desire the...

Hi Guys, I have been assigned a task to automate the movement of a Human Body (We are using a Human Dummy) using Python Scripting. The Input for this tasks are the Joint Angles (Perhaps similar to a Robotic Joint). We use the terminology of R,S and T to represent Rotation around the Three...

Hi Friends, The code below is for 2D ploting in Matlab, I want to change it in 3D, please if anyone know how to do this.let me know thanks in advancefigure(1); popcosts=[pop.Cost]; repcosts=[rep.Cost]; plot(popcosts(1,:),popcosts(2,:),'b.'); hold on; plot(repcosts(1,:),repcosts(2,:),'r*'); hold...

In my project I basically need to plot 3D color coded surface graphs using MATLAB taking input from multiple .dat files (i have 1000 .dat files). In each file I have parameters x and y, and when I take multiple files, each having a different value of z, I can finally plot a graph. so does anyone...

I hope this is the right forum... In 3d space, a 2d plane can be specified by it's normal vector. In 4d space, is there a 3d plane, and will these planes be specifiable by a single vector?

Homework Statement Hi there! Here is a problem from our 1st year course. We have covered the basics on charges and Coulomb's Law. However our prof said he designed the following question to be "deliberately obscure"! Two charges of 4.00μC are fixed in space, Q1 at (0,0,0) and Q2 at...

Hey there, first time posting, I have casually browsed this forum for a while. Anyway on to the question, I am trying to solve in the best way possible the N-Body problem, I am at a complete loss, I have no idea what I can do, I have tried figuring out my self different integrators such as...

Homework Statement Calculate the flow of ##\vec{F}=(y^2,x^2,x^2y^2)## over surface ##S## defined as ##x^2+y^2+z^2=R^2## for ##z \geq 0## with normal pointed away from the origin.Homework Equations The Attempt at a Solution The easiest was is probably with Gaussian law. I would be really happy...

Hi all, How can I calculate the minimum distance between the perimeter of a disk in 3d space and a point above the disk? (the point can be inside or outside the area above the disk) I've been trying to work this out for a while, but I'm getting no where. For example, a point at (1,1,1)...

Homework Statement find the length of a circular helix expressed in parametric form x= cos(t), y=sin(t) and z = t from t = 0 to t =2pi Homework Equations L = integrate ds (ds)^2 = (dx)^2+(dy)^2+(dz)^2 The Attempt at a Solution I got to ds = (1 + (dt)^2)^0.5 but I can't...

Hi, Given 3D points P1(200,60,140), P2(300,120,110), P3(3,0,-1), P4(-100,0,-1) and the radius of arc C1MP3 is equal to radius of arc C2MP1. How do I calculate coordinates x, y, z of points C1 and C2? Points C1 and C2 are centers of two reverse arcs which are tangent to each other at point...

Hi, Given 3D points P1(200,60,140), P2(300,120,110), P3(3,0,-1), P4(-100,0,-1) and the radius of arc C1MP3 is equal to radius of arc C2MP1. How do I calculate coordinates x, y, z of points C1 and C2? See this image. Points C1 and C2 are centers of two reverse arcs which are tangent to...

Does anyone know how I might go about graphing the Z-Transform in 3D? It want it to look something like the picture below.

I'm so confused about finding an angle, theta in this illustration. With having three coordinate information, how can I calculate the theta using dot product? I would easily find the angle by using trigonometric formula if I ignore the z-axis. But I want to solve this problem with...

Question: Write a vector equation which has an x-intercept of 3 and a z-intercept of -1 I want it in the form of (x,y,z) = (p1, p2, p3) + t(d1, d2, d3) I don't have a clear idea on how to solve it.

Homework Statement A particle P is free to slide on a smooth wire which has the form of a helix, with a position vector given by: r((t)) = a cosθ(t)i + a sinθ(t)j + bθ(t)k The particle is released from rest at the point (a, 0, 2∏b). Using energy conservation for conservative...

Homework Statement Consider a particle confined in a cubical box with the sides of length L each. Obtain the general solution to the eigenvalues and the corresponding eigenfunctions. Compute the degeneracy of the first excited state. A perturbation is applied having the form H' = V from 0...

Homework Statement Let P, Q, and R be the vertices of a parallelogram with adjacent sides PQ and PR. Find the other vector S. P (2, 0 ,-1), Q (-2, 4, 1), R (3, -1, 0) Homework Equations PR = QS PQ = RS The Attempt at a Solution I took the two equations and solved both of them...

In this problem I have drawn out the region specified and noticed two sets of parallel lines indicating to me that a change of variable(u and v) are able to be used to solve this integral. I decided that u=y-x and v = -2x-y then solving for x and y I obtain x= (u-v)/3 and y = (4u-v)/3 From...