3d Definition and 1000 Threads

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...

$\textsf{graph the given}$ \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?

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...

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.

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...

Hello Forum, I am new to 3D printing and wondering if any of you have been able to print transparent plastic object with 3D printing. It seems that translucency is the best that we can get. Is that true? Are today's affordable 3D printer still only work with PLA and ABS or are there other more...

Looking for Something durable yet Very Light 3D printing material. I googled and Found A product. http://www.mes3dfilaments.co.uk/product/form-futura-carbonfil Carbon Fiber PLA.. Any other suggestions? For application for small wind turbine propellers

Here are several 3D printer art creations by Henry Segerman I came across on the Shapeways site. I found them interesting. I especially liked the ones that projected interesting shadows when illuminated from within (like a lamp).

Homework Statement Find the value of ez if e = 1/3i + 2/3j + ezk Homework Equations Any help? The Attempt at a Solution Have no idea where to start

Homework Statement [/B] Given a rectangular parallelepiped ABCDEFGH, the diagonal [AG] crosses planes BDE and CFH in K and L. Show K and L are BDE's and CFH's centres of gravity. I think I have understood the problem, could you verify my demo please ? Thanks Homework Equations The Attempt at...

Imagine a point with n vectors (all with equal magnitude) coming out from that point that equally cancel each other out in magnitude. How would you calculate the equal angle between n vectors? For example: 2 vectors (equal magnitudes) coming from one point that cancel each others magnitude...

Homework Statement Calculate the single-particle density of states ##g(\epsilon)## for the dispersion relation ##\epsilon(k) = ak^{\frac{3}{2}}## in 3D. Use ##g(k) = \frac{Vk^2}{2\pi^2}##. Homework EquationsThe Attempt at a Solution This question is worth lots of marks. My solution is a few...

I know cylinder, cone and cube, but can't think of the names for the last two. I know this is a very basic question that I should know...but I am blanking.

Homework Statement There's a person on the ground in (0,0,0). An object comes from the sky and hits the ground at (a,b,0), but continues propagating, that is, it does not stop. I need to find the minimum distance between the person and the object. All we know is that the person is in (0,0,0)...

Hi to everyone, I'm trying to plot a 3D graph on MATLAB but I do not know how. The function that I want to plot is: y=fminbnd(@(x) wei(x,shape,scale,tw,tf),x0,x1). I would like to plot the minimization of the function wei (y) in function of the shape and the scale. Wei is a function that I...

Hi! I'm looking for anyone that has had experience with 3d Bioprinters. At the same time, I'm looking for the characteristics it needs to have in order to function without a sterile hood. Factors such as sterilization, CO2, and humidity concentration. For example, for sterilization, I have...

Hello, I'm a sci-fi author and need to plot a course with distances and galaxy (cluster and super cluster) stop overs between the Coma Wall, Earth and the Great Attractor. I've looked at a few online 3D universe maps and 2D maps but have not found anything ideal. Any suggestions? Thanks so...