3d Definition and 1000 Threads

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, I'm attempting to solve the 3D poisson equation ∇ ⋅ [ ε(r) ∇u ] = -ρ(r) Using a finite difference scheme. The scheme is simple to implement in 3D when ε(r) is constant, and I have found an algorithm that solves for a non-constant ε(r) in 2D. But I am having trouble finding an algorithm...

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...

Homework Statement The 25-kg rectangular access door is held in the 90° open position by the single prop CD. Determine the force F in the prop and the magnitude of the force normal to the hinge axis AB in each of the small hinges A and B.[/B] Homework Equations ΣF=0 ΣM=0 [/B]The Attempt at...

Hey guys, so I'm currently writing a math exploration paper on modelling the optimal tennis serve. I am using Geogebra and I was wondering if you could help me come up with the equation that will help model the trajectory of the tennis ball over time given the following conditions: 1. Initial...

Homework Statement Find the curvature of the car's path, K(t) Car's Path: r(t) = \Big< 40cos( \frac {2 \pi}{16}t ) , 40sin( \frac {2 \pi}{16}t ), \frac{20}{16}t \Big> Homework Equations K(t) = \frac { |r'(t)\:X \:r''(t)|}{|r'(t)|^3 } The Attempt at a Solution This is part of a massive 6...

Suppose we have do a curl of two 2-d vectors... we get the 3rd axis about which it is rotating. But when we do the curl of two 3-d vectors.. we get a answer like x-y plane is rotating wrt z axis, y-z plane rotating wrt to x-axis and similarly x-z plane rotating wrt to y axis. My question is...

Could a 3D printer print its own ink, plastic filament, motors or anything / everything else that it uses to operate and print?

Dear all can anyone help me to understand why gravity in 3 dim doesn't have local degree of freedom. How can i compute the degree of freedoms for gravity in and dimension D. If i consider massless gravity in 3d is the graviton propagating

The spherical oscillator problem is for a potential centered at the origin.. but what if the particle is confined to oscillate at a small shift by a small (not infinite) barrier? The potential is now centered about the new position.. Could someone please suggest a way to solve the problem for...

If you were to look at a simple 2D or 3D static equilibrium diagram, where a mass is suspended by multiple ropes at different angles, my gut feeling is that there is a fairly simple proportion between the distance between the center of mass and the rope (the distance created opposite of the...

Homework Statement Find the directional derivative using ##f\left(x,y,z\right)=xy+z^2## at the point (4, 2, 1) in the direction of a vector making an angle of ##\frac{3π}{4}## with ##\nabla f(4, 2, 1)##. Homework Equations ##f\left(x,y,z\right)=xy+z^2##The Attempt at a Solution I found the...

In 1-dimensions, the final orientation after undergoing constant angular acceleration is: \theta_f = \theta_0 + \omega_0 t + 0.5 \alpha t^2 What is an analogous equation in the 3D case? In other words, if I know the initial orientation (say, as a quaternion), angular velocity (as a 3-vector...

Hi, For a harmonic oscillator in 3D the energy level becomes En = hw(n+3/2) (Note: h = h_bar and n = nx+ny+nz) If I then want the 1st excited state it could be (1,0,0), (0,1,0) and (0,0,1) for x, y and z. But what happens if for example y has a different value from the beginning? Like this...

Homework Statement You wish to find the moment at the origin produced by a force, ̅F= {Fi}̂, that is applied at r= {̂ai+bj +ck ̂}. Which variables (F,a ,b,c , ) do we need to know to find a numerical answer? Explain using math and figures. Homework Equations Mo = r x F The Attempt at a...

Dear everyone,Direction Write the vector in component form. v lies in the yz planeplane, has magnitude 2, and makes an angle of 30 degrees with the positive y axis. Work I know that the x component is zero. <0,v1,v2​> Thanks Cbarker1

Is there any good, preferably available for macs, and much preferably free 3d physics simulators, in the spirit of Algodoo, or something similar? I have found Algodoo very enjoyable to play around with and very useful to help visualize certain systems and "confirm" any equations I derive for...

I'd like to expand a 3D scalar function I'm working with, ##f(r,\theta,\phi)##, in an orthogonal spherical 3D basis set. For the angular component I intend to use spherical harmonics, but what should I do for the radial direction? Close to zero, ##f(r)\propto r##, and above a fuzzy threshold...

I know I'm not in the right space for thise, nor smart enough to be here, but iplan on seeing Suicide Squad Friday at IMAX. Icant use those red and green glasses they have because I have a azy eye and the don't work compatibly with each other. I just heard of IMAX RelD 3D and was wondering if...

There are links in the article to more science-oriented reports. http://www.csmonitor.com/Science/2016/0715/Scientists-create-huge-3-D-map-of-universe-validating-Einstein-s-theories That would be a great use for some of those Virtual Reality goggles.

Homework Statement An isotropic harmonic oscillator has the potential energy function U = 0.5 k (x²+y²+z²). (Isotropic means that the force constant is the same in all three coordinate directions.) (a) Show that for this potential, a solution to the three dimensional time-independent...

So having considered the classical depiction of a black hole resembling a whirlpool, my thought process is that a black hole must be a 3-d phenomenon. Therefore I can not see how a event horizon/swirlpool model could be plausible unless the centre of a black hole was spinning and literally was...

From the perspective of a 4D observer would 3D infinity appear to exist? Why/why not?

Hi, I know how to calculate density of states for both cases, but it is not clearly to me how I can go from 3D case to 2D. I have energy from infinite potential well for 3D $$E=\frac{\hbar \pi^2}{2m}(\frac{n_x^2}{l_x}+\frac{n_y^2}{l_y}+\frac{n_z^2}{l_z})$$ let make one dimension very small...

First, I'd like to say I apologize if my formatting is off! I am trying to figure out how to do all of this on here, so please bear with me! So I was watching this video on spherical coordinates via a rotation matrix: and in the end, he gets: x = \rho * sin(\theta) * sin(\phi) y = \rho*...

Homework Statement The plate has a dimension of 460mm X 260mm, subjected to a central load of 400N. Determine the reaction A and B, each representing a roller support as a wheel, located at the center of one edge. (opposite blue arrows have the same resultant value.) Are they the same ? If not...

Greetings. I'm working on a raytracer, and got stuck with trying to model a lens analytically. Given is a thin lens at position p with the axis n, radius r and a focal distance f, a ray hits it at position p1 going in the direction d. Which way would the ray be going on the other side of the...

Does anyone know of galactic rotation data (any galaxy) of the following form: For simplicity assume an [x y z] coordinate system with the origin in the center of the galaxy and [x y] representing the plane of rotation. At any point [x y z] there is a corresponding velocity vector [vx vy vz]...

I read more and more news about what 3d printers created. I wonder about two things. Can they create engine parts that has to be durable, withstand big stress? Could they do it cheaper than old fashioned ways of forging metal? Also they write about 3d printed organs, but are they rather like...

Homework Statement 6 degenerate energy states at E=7/2 h-bar w in isotropic 3D harmonic oscillator. pick one possible state( for example, (nx,ny,nz)=(1,0,1)), and find possible l, m quantum numbers you may use orthonormality of spherical harmonics[/B] Homework Equations pick one possible...

Homework Statement The points A,B and C have position vectors , relative to the origin O given by ## OA= i+2j+3k, OB=4j+k , OC=2i+5j-k.## A fourth point D is such that the quadrilateral ABCD is a parallelogram. i) Find the position vector of D and verify that the parallelogram is a Rhombus...

I used a function called ind2patch to make a big 3D block which contains a number of smaller blocks in 3 dimensions. Each small block has a value which the magnitude is represented by a color.One example is shown below: However, most of the boxes have very low or zero value and I don't need to...

Hi everyone! I have the following problem. I have a two phase flow in a circular pipe and I want to model it. I need to decide and justify whether the model should be 2D or 3D. For the moment, I can say only one thing: considering z-axis in the length direction (that it is the dominant one) I...

According to Aufbau principle energy of 3d should be greater than 4s but here 4s is having higher energy. Please anyone explain this.

Homework Statement Silicon crystalises in a cubic structure whose lattice is face-centred, with a basis [000],[1/4,1/4,1/4]. How many optic/acoustic modes are to be found in the phonon dispersion diagram for silicon. How many distinct branches would you expect along the [100] direction...

I just want to know how to visulize 3D solution in MATLAB by different ways So please I need some help.

Homework Statement Find the volume of the given solid. Bounded by the planes z = x, y = x, x + y = 5 and z = 0 Homework Equations V =...

Could anyone please recommend any papers that describe the path of a 4D ball through 3D space?

Homework Statement Homework EquationsThe Attempt at a SolutionFree body diagram Setting moment at the origin = 0 (Rb X B) + (Ra X A) + (Rc X C) = 0 solving the 3 determinants and setting the coefficients of i, j, and k to 0, I get: 8Bz - 10 Cy = 0 -12 Az + 10 Cx = 0 12 Ay - 8Bx = 0 I...