3d Definition and 1000 Threads

<<<moved from another sub forum, no template>>Hi, I need to calculate the moment of inertia for the component in the attached image so that i can calculate the angular momentum. Is it possible? Overall i am trying to calculate the forces on this lug as it passes around a 3" radius at 2M a...

Hi all, I have a problem with a 3 wheel trailer and sizing the wheels. Using statics, how would I solve this 3D problem by breaking it down? The trailer is sitting on rectangular section and a plate on top carries an even load of 3500kg (roughly 35kN) If I take a cross section A-A and try and...

Hello, an engineer here that is trying to understand more in topology for some mechanics ideas. It seems to me that any closed (regular) manifold in 3d Euclidean space should be able to be describe uniquely by the combination of the following 1) volume [1 real], 2) centroid [3 reals], and 3)...

Homework Statement Let r be a positive constant. Consider the cylinder x2 + y2 ≤ r2, and let C be the part of the cylinder that satisfies 0 ≤ z ≤ y. (1) Consider the cross section of C by the plane x = t (−r ≤ t ≤ r), and express its area in terms of r, t. (2) Calculate the volume of C...

This is only the third thing that I've created in 3D modeling. If you played the PC video game Quake 2 back in 1998, then you might remember this. https://imgur.com/a/dqEqD

This may belong to the computing subforum, let me know if this is more true than having it here in the math forum :) My questions are 1) Suppose there is a plane in 3D space and I have 3 points to define it: p1 = {x1, y1, z1} p2 = {x2, y2, z2} p3 = {x3, y3, z3} and I want to put a particular...

Homework Statement Three close-packed planes of atoms are stacked to form fcc lattice. The stacking sequence of the three planes can be altered to form the hexagonal close packed structure by sliding the third plane by the vector r over the second. If the planes in the fcc structure are all...

This has been a real famous analogy and I understand it, except the fact that the balloon surface is a 2D structure. How is it possible to depict a 3D universe on a 2D plane ? What happens when we work with stars at multiple planes ?

In poisson's ratio If we are stretching a a 3d rectangle L is hight A,B are the length and width Starching it in the L direction so that's the longitudinal strain we are making Why does the transverse strain in the "a " side equals the strain in "b" side So like that we can both use ∆a/a or...

Here are screenshots of a 3D model I made using a program called Blender, of the RBMK-1000 "Chernobyl-type" nuclear reactor and reactor hall. It's still a work-in-progress and not yet finished. https://imgur.com/a/rpHnK

Hello, I have some simple 3d data like, point 1: x1 = 5.8573375, y1 = -4.17885, z1 = 2.338175 point 2: x2 = -3.26132, y2 = 1.28276, z2 = 0.931583 I need to be able to extend the line from point 1 through point 2 to some additional distance. There are a few posts on stackexchange, but they...

Hi PF! I'm trying to plot in 3D. I have ##r = f(\theta,z=0)## and it plots well. However, I would like to plot ##r = f(\theta,z)## in 3D. Any idea how to do this? The radius is actually a separable function ##r = h(\theta)g(z)##, so I have ##h## plotted for a given ##\theta## vector and ##g##...

Homework Statement Homework Equations M=r x F = d * F (for moment couple) The Attempt at a Solution This is my attempt to the question, yet I have got quite a different answer from my classmates... (especially the moment by the 50N force couple) Can anyone point out is there anything wrong...

$\textsf{Find the area of the triangle determined by the points }$ \begin{align*}\displaystyle &P(1,1,1), \, Q(-2,-7,-1), \, R(-7,-1,4)\\ \end{align*} \begin{align*}\displaystyle \vec{PQ}&=(-2-1)i&+(-7-1)J&+(-1-1)k&=-3i-8j-2k\\ \vec{PR}&=(-7-1)i&+(-1-1)j&+(4-1) k&=-8i-2j-3k...

Homework Statement I have been thinking about this problem for comparison of experimental data to theoretical for a project. A hammer with known mass mh and mass moment of inertia Ih is held stationary at 90 degrees. It is released as swings down. At 0 degrees it impacts a block, initially...

$\textsf{graph the given}$ \begin{align*}\displaystyle y^2+z^2&=16\\ x&=5 \end{align*} ok I know this is circle $||$ to the yz axis 5 units away but want to show this circle on a 3d view (tried W|F but 😰) ok found this the parameterization of radius r around the axis, centered at...

If you have a rectangular box connected on 3 sides with strings, and you hold all the strings together at a point, with your hand; then you put a weight in the center of the box, which is open, would the tension on the strings differ than if you put the weight at a corner. Please describe it to...

A fictitious system having three degenerate angular momentum states with ##\ell=1## is described by the Hamiltonian \hat H=\alpha (\hat L^2_++\hat L^2_-) where ##\alpha## is some positive constant. How to find the energy eigenvalues of ##\hat H##?

Hello, Im creating a physics simulator and I am struggling to expand my collisions from 2D to 3D. In 2D the velocity only changes parallel to the line of center so I presume this is the same for 3D.I can get a Cartesian equation of line but I am not sure how to get the velocity component...

To find potential energy in 3 dimensions why do we take partial derivative and not total derivative?

Hello Everybody! Concept of Solid Angle was pretty much straight forward until they were on surface patches were taken into account which were visualized as base of cone. I am having difficult when 3d Objects like Sphere/Cylinder . We can very easily calculate the respective area and plugin the...

Homework Statement A 200N force is applied to the handle of the hoist in the direction shown. The bearing A supports the thrust (force in the direction of the shaft axis), while bearing B supports only radial load (load normal to the shaft axis). Determine the mass 'm' which can be supported...

I am trying to assemble an optical tweezers setup and was thinking if it is realistic to assemble an optical tweezers setup using 3D printed parts? Also can DMD (Digital Micromirror Device) be used instead of SLM to manipulate the beam and generate multiple traps?

Thank you for your interest and please let me know what you think! Here is the video link: Here is the video description: "3D Origami Paper Swan" Instructions for how to make the triangles here: https://www.youtube.com/watch?v=74z3n... This project took about a month to finish. I did not...

Hello, can anyone explain me how optical system of a structured light 3d scanner like this one works? I tried to google it, but still didn't understand how it get's Z coordinate.

This article from 2013 says that the 3D printers available to hobbyists are similar to "project cars". You spent most of your time trying to adjust and fix the machine instead of using it...

Hi, i am 3D Artist and create 3D visualizations like this. Now I want generate a 3D animation about science fiction like star wars. Can I create a 3D animation about Star wars or I need a license of lucasarts. Thanks.

Homework Statement q1= 5 x 10^-6C position (1;2,-1) q2= -3 x 10^-6 C position (-2,1,3) a) what is the electric force caused by q2 on q1? (vector notation) b) what is the electric field at (0,0,0) Homework Equations F = kq1q2/r^2 E= F/q The Attempt at a Solution I really don't...

Homework Statement Plot the electric potential ##V(r)## due to a positively charged particle located at the origin of an XY plane. Homework Equations ##V=\frac 1 {4πε_0} \frac q r## The Attempt at a Solution I'm unfamiliar with 3D coordinates at this time, but I like to know how can I plot it...

Homework Statement Hi everybody! In my quantum mechanics introductory course we were given an exercise about the 3D quantum harmonic oscillator. We are supposed to write the state ##l=2##, ##m=2## with energy ##E=\frac{7}{2}\hbar \omega## as a linear combination of Cartesian states...

Hello, I am trying to recreate a shape shown in the attached photo, from the attached article I have tried to create this shape in MATLAB as shown in the code bellow , from this formula i get a 2D shape and not the shown 3D shape , how to create this 3D shape? Thankstheta_0=15; alpha=60...

So at work I am baffled by a problem to bend a flat plate (3mm thick max) using string where the string is encased in the plate. So naturally I 3d printed some plates and attached a string but found as suspected that the plate would only bend when the string had some angle > than a few degrees...

Browns, Reds, and Blues have been 3D printed (video here) by making very tiny shapes similar to those that underlie the iridescence phenomena. This kind of coloration is in some ways similar to the another favorite of mine (which I would call a structural non-color): Vantablack (Vertically...

Please help me solve a problem that has puzzled me for years. I am not a mathematician or a physicist, so please bear with me. Imagine the apparatus pictured to be a depiction of the x, y and z axes. The x is represented by the green stick. The y is represented by the yellow stick, and the z...

I am doing some mathematical exercises with 3D anti-de sitter face using the metric ds2=-(1+r2)dt2+(1+r2)-1+r2dφ2 I found the three geodesics from the Christoffel symbols, and they seem to look correct to me. d2t/dλ2+2(r+1/r)*(dt/dλ)(dr/dλ)=0...

This video is about making a snake out of paper. The style of paper folding and structure building shown in this video is called "3D Origami" if you wish to look it up. I hope that this video will inspire you guys to create your own creations and share them with me. I learned this skill in 6th...

∴1. Homework Statement Find an equation for the plane that contains the point (1,-1,2) and the line x=t, y=t+1, z=-3+2t? 2. Homework Equations The Attempt at a Solution I don't know what I am doing wrong but everytime I try to do these plane questions my amswer is always the opposite sign of...

Hi all, I need an algorithm that fills a 3d lattice from any point, always expanding (no return allowed as in ref. http://msl.cs.illinois.edu/~lavalle/papers/KufLav09.pdf). The cells must be visited just once. My efforts are contained in the attached file. It works ***almost*** correct. Some...

Hey! I hope this is the right place to post this. I'm looking for recommendations for a modeling/drafting cad program that is relatively affordable and capable. I have extensive experience with NX and Solidworks, but can't justify paying for either of those to simply use at home. My non-work...

I'm trying to build a software function that explores a 3d grid visiting the cells just once. The file below is my last attempt, which misses some cells (for 16x16x16 it visits 3436 cells instead of 4095). Can anyone give me a reference to a solution, please.

Hello all, I am working on a simple induction system consisting of 2 coils (separated by a distance) and the ferrite cores modeled with Maxwell 3D I want to run the optimization tool to define the best distance between the coils in order to have a high coupling factor between them. I am...

I have a design I want to 3D print. It's tiny, less than 1 inch, and has more than one fitted, moveable part. I'd like to figure out if it's feasible before I decide whether I buy in. I don't know what software is used to make the designs. (A friend told me his printer supports .stl files) I...

I know that the generalization of parallel lines to curves in 2D is just "parallel curves", but is there any term which generalizes the idea of skew lines to curves? "Skew curves" doesn't work, this term already being co-opted by statistics. Example: if you had two curves coiling around each...

This little article discusses a variety of savings GE got from using 3D printing in making a new turboprop engine. They included fewer parts (855 --> 12), subsystems (40 --> 1), and suppliers (50 --> 1).

Homework Statement An electric dipole with magnitude ##p = 0.2Cm## is placed inside a uniform electric field of ##\vec{E} = 100\vec{i} + 70\vec{j} + 40\vec{k} \frac {N} {C}##. The dipole was initially pointing along the +x direction. You then start to rotate it first on xz-plane towards...

Homework Statement Let γ : I → R3 be an arclength parametrized curve whose image lies in the 2-sphere S2 , i.e. ||γ(t)||2 = 1 for all t ∈ I. Consider the “moving basis” {T, γ × T, γ} where T = γ'. (i) Writing the moving basis as a 3 × 3 matrix F := (T, γ × T, γ) (where we think of T and etc...

Hi, i want visualize a 3D configurator like this in reality. I have print the configurator in 3D but the result was not very good. How I can visualize the 3D configurator in reality in best. Thanks.

$ \tiny{231.14.88}\\$ $\textsf{Identify and briefly describe the surface of the equation}\\$ \begin{align*} S_{88}&=\frac{-x^2-y^2+z^2}{9+6x-8y}=26 \end{align*} $\textit{this had no template example but on}\\$ $\textit{ W|A it looked like a torus?}\\$ $\textit{where is a good online 3d graphing...

Suppose we wish to use Cartesian coordinates for points on the surface of a sphere. Then all derivatives of the metric would vanish and so the Riemann curvature tensor would vanish. But it would give us a wrong result, namely that the space is not curved. So it means that if we want to get...

I was just thinking about this randomly today. I feel like the answer is that it "does" and it "doesn't." A math teacher I had said that the 4th dimension is perpendicular to everything and anything in the 3rd, so does that mean that it can't be displaced, or is the answer more complicated than...