2d Definition and 1000 Threads

Hi everyone, As part of a project, I am required to numerically compute the expression b_{i}^{e} &=& \frac{E_{0}^{i}k_0^2(\epsilon_r-1/\mu_r)}{2\Delta^e}\left[\iint\limits_{\Omega^e}(a_i^e + b_i^e x + c_i^e y)e^{-jk_0 x} dx dy\right] \nonumber\\&&- \frac{jk_0 E_0^i r'}{2\Delta^e...

Hello--- I am reading a paper which presents a method to determine attenuation (and Q factors) from reflection seismic data (Y. Wang, "Q analysis on reflection seismic data," Geophysical Research Letters, Vol. 31, 2004). To perform signal processing on a seismic trace, the paper describes...

Solving 2D Poisson problem with a single series! Conventional solution of \nambla^2u(x,y)=f(x,y) involve solution u(x,y)= \sum_{n=1}^{\infty} \sum_{m=1}^{\infty}E_{mn} sin(\frac{m\pi}{a}x) sin(\frac{n\pi}{a}y) This is a two series solution which is tedious to solve. The book PDE by Asmar...

I've been trying to evaluate an integral for the last few days now and it really has me stumped. I was hoping that maybe someone here would be able to help me out. So the function, cov(x,x'), is fairly basic. It's called a squared exponential covariance function and it evaluates the covariance...

Dear users, I wonder if there is anybody who can give me a hint on how to handle the following situation: In the 2+1 dimensional Klein-Gordon equation with coordinates (t,x,y), I use as initial condition for \Psi(x,0) a spherically symmetric Gaussian. The relativistic dispersion relation...

Homework Statement In a local bar, a customer slides an empty beer mug down the counter for a refill. The bartender is momentarily distracted and does not see the mug, which slides off the counter and strikes the floor 0.40 m from the base of the counter. The height of the counter is 0.730 m...

Homework Statement A rocket is launched at an angle of 53 above the horizontal with an initial speed of 75 m/s. It moves for 25s along it's initial line of motion with an overall acceleration of 25 m/22. At this time its engines fail and the rocket proceeds to move as a freebody. a) What...

hi. i have a quick question regarding fortran 90. i often need to add a vector to a 2d dimensional array, and i find it a bit to 'bulky' to always use do loops. let's say i have this: do i=1, 20 a(:, i)=a(:, i)+b(:) end do is there a simple(r) way to tell fortran that i want to...

I'm trying to do FFT convolution via the FFTW3 library for image processing purposes. Basically I have a kernel and I am convolving it with an image. A problem I encountered has to do with the dimensions of the image. When the width is not equal to the height, the pixel values I get, seem to...

I need a fem code either in MATLAB or fortran to refer to as I am stuck at some places. Please help.

Homework Statement I need to be able to get a equation to figure out the initial speed as an object leaves the origin, and I don't understand what exactly I am suppose to treat these as? Basically they are showing us vectors, Vo being velocity vector, and Vox and Voy being x and y components...

Homework Statement I have a 2D isotropic mass-spring system. The mass is pulled a distance A=1m, and then given an upwards kick with a velocity v_0. The k=1, m=1kg. I need to find the furthest distance from the origin the mass will travel in its orbit. Homework Equations x(t)=A_x\cos(\omega...

the question and solution after i they find the total interval of the total function i can't understand what they do with the graph and how they derive the integrals from it ?

Homework Statement I apologize in advance for my inability to present formal equations here. I'll do my best to be clear with the representation using simple text. "Use the Jacobian Matrix to Prove Laplace's 2D Eq.: (partial^2 u)/(partial x^2) + (partial^2 u)/(partial y^2) = 0"...

Homework Statement A baseball player friend of yours wants to determine his pitching speed. You have him stand on a ledge and throw the ball horizontally from an elevation 3.00 m above the ground. The ball lands 30.0 m away. A) What is his pitching speed? B) As you think about it, you’re...

in a jar we have 3 balls one red one white one black 3 people choose a ball and return it back. x represents the number of different colors which the 3 people chose y represents the number of white balls chosen. p(x,y) find p(2,0) we have in total 27 possibilities 3 people chose...

Homework Statement A small sphere is dropped from rest at a height 'h' above a plane inclined at an angle θ to the horizontal ( < 90degrees ). Given that the sphere loses no energy on impact, show that the distance down the plane between this impact and the next is 8hSinθ. Homework...

we throw 3 coins y represents the throw of three coins x represents the throw of the first two we count the number of hetz gotten from the thrown coins. the solution says for the slot that: P(x=1,y=2)=0.25 but i can't understand how ? the logical solution says: for x to be 1 we have 01 10 so...

Homework Statement A dolphins leaps out of the water at an angle of 35 degrees above the horizontal. The horizontal component of the dolphin's vleocity is 7.7 m/s. Find the magnitude of the veritcle component. Homework Equations I'm not sure what equations to use. The Attempt at a...

Homework Statement A football player throws a football at 40 degrees. A stationary player 31.5m downfield is ready to catch the ball. At what velocity does the player have to throw the ball in order to reach the downfield player? We were told the correct answer is 17.7m/s Homework...

Good day to all, 1) I find difficulty on putting two 2D graphs into one figure. If same command it is easy to do but i have different commands, the commands are listlineplot and plot...

Delete.. Delete..

Homework Statement Plate in the shape of the circular halo (inner radius a, outer radius b>a), the inner edge is being kept at a constant temperature T_0, and the outer at the temperature given by the function f(\phi)=T_0\cos(2\phi). Find the equilibrium distribution of the heat everywhere...

i am now reading the book by landau 'the classical theory of fields' it seems that to develop the relativity theory of einstein, only two postulates are needed the first one is relativity the second is no instantaneous interaction therefore, einstein's theory can be developed in...

Homework Statement Evaluate the following definite two-dimensional integrals over the specified domains of integration. f(x,y)=min(x,y), over the region {(x,y) : 0 \leq x \leq 2, 0 \leq y \leq 1} Homework Equations The Attempt at a Solution I'm not even sure where to start...

Homework Statement 3. A cannon ball is launched from a cliff with an initial velocity of 50 m/s 300 above the horizontal. If it’s range is 300 m. a)What is the height of the cliff? b) What is the impact velocity of the ball right before it strikes the ground? Homework Equations...

I have two balls with d1 and d2 as their direction, and I have the speed s1 and s2, d1 and d2 are in radians showing the angle made with positive direction of x-axis and in anticlockwise direction i.e 0<=d1 and d2<2*pi their positions are (x1,y1) and (x2,y2) when they collided after...

Homework Statement In a Fourth of July celebration, a firecracker is launched from ground level with an initial velocity of 25.0 m/s at 30' from the vertical. At its maximum height it explodes in a starburst into many fragments, two of which travel forward initially at 20.0 m/s at \pm53.0'...

An object is projected horizontally with an initial velocity of 3.0m/s A) When will the vertical displacement be 5.0m B) What will the horizontal displacement be at this time Have difficulty's with A

I studied in AMO physics. nowaday, I study about BEC. I'm wonder, Difference between 1D lattice and 2D lattice on BEC. In the web, they just explain what they do using that. Maybe just short word, or sentence, give me a huge knowledge. Thanks you, and Have a nice day!

Hi, I was attempting to work through this question. Anyways, I was working from a graph, so the radius 2.5 cm, the two of them collided, it was an inelastic collision as the two objects did part ways, so how do I find the centre of gravity? I attempted to calculate it... but if someone could...

Hey all, This is a bit of a broad subject so I'm not sure which section it best applies to, but here it is anyway. I'm working on a massively over-engineered version of the original Asteroids game. How over-engineered? Well the problem I have right now is desigining and implementing a...

I want to know this information, I am going to study autocad, my friends are telling to learn how to do 2d and then go for 3d , what is so special in 3d AUTOCAD drawings, anyone here in this forum can explain it.

Hi, I am trying to find an expression for the density of states of free two-dimensional electrons, as a function of energy, and I am really struggling. I get that what I am looking for is the number of states per unit area of k-space per unit energy, and in general (3D), this is expressed as...

Homework Statement You are moving due North in your car with velocity (0, 20m/s). You see another car traveling with a relative velocity of 15 m/s with an angle of 150 degrees. You have a mass of 30 kg, the other tricyclist has a mass of 40kg and the tricycles both have mass 10kg. You...

Homework Statement Two masses, m1 = 4 kg and m2 = 12 kg, have initial velocities of v1i = 28 m/s [+x 35 +y] and v2i = [-y 60 +x]. If the first mass has a final velocity of v1f = 18 m/s [-y 40 +x], find: a). The final velocity of m2. b). Whether or not the collision can be said to be...

Well, finals are coming around. I'm reviewing stuff I thought I learned at the beginning of the semester only to find out that I don't remember what I'm doing. It's pretty easy until I forget everything. I think I have a handle on this, but I just want some verification to make sure I'm doing...

Homework Statement A cannonball is fired from the ground at an angle of 50 degrees. The ball lands 67 meters from where it was fired. Air resistance is negligible. How long was the ball in the air? With what velocity was the cannonball fired? Homework Equations Xf=.5at2+Vot+Xo...

I have to write a FD expilicit method, for temp dist on 2D plane. I am trying to mod the 1D solver to 2D solver, the code below is a 1D solver. Any possible suggestions how it can be done? I initially, derived u(i,j+1) for 2D for in that derivation i,j corresponds to x,y... where as in 1D...

Homework Statement We have two pucks next to a wall. Puck 1 has velocity v0=15 m/s in the direction y (as seen on the picture). Puck 2 is stationary. After the collision puck 1 moves in the opposite direction with velocity v1=10 m/s and puck 2 moves with unknown velocity in the direction x. The...

I am working on a simulation of a ball moving in a complex 2d environment. I am looking for a single physics model that will handle the movement of the ball properly. Here is exactly what I have: Gravity applied in the -y direction Friction and wind resistance collision detection with the...

Homework Statement An Alaskan rescue plane drops a package of emergency rations to a stranded party of explorers. The plane is traveling horizontally at 100 m/s at a height of 50 m above the ground. What horizontal distance does the package travel before striking the ground? what is the...

Homework Statement Calculate the area of the region within x3 + y3 = 3xy. It can be parametrized by \gamma:[0,\infty] \rightarrow R2 with \gamma=<3t/1+t3, 3t2/1+t3>.Homework Equations Area = 1/2 \intx*dy - y*dx The Attempt at a Solution My plan is to take the curve parametrized by...

Homework Statement Given f(x,y) = DeltaFunction(y - x*tan(theta)) a) Plot function. b) Take Fourier transform. c) Plot resulting transform. Homework Equations Delta function condition non-zero condition DeltaFunction(0) = Infinity Sifting property of delta functions The...

Hello, I would be grateful if someone could comment on my problem. I am trying to simulate diffraction of optical wavelength on a sub-wavelength aperture (aperture diameter/wavelength < 0.1). What I want to achieve is: - simulate a geometrical model with an aperture of 15um diameter -...

Homework Statement Two coins, one at rest (c1), the other flicked towards the other (c2). Initial positions are marked, as are final positions and angles. Coordinate system's origin is placed at center of C1 with +x in direction of C2's motion. knowns: \mu = .36 V1 = 0 C1 final position- 10.25...

Homework Statement A softball is hit over a third baseman's head with some speed v-sub0 at an angle theta above the horizontal. Immediately after the ball is hit, the third baseman turns around and begins to run at a constant velocity V = 7.00m/s. He catches the ball t=2.00sec later at the...

don't get this 2d motion problem?? Homework Statement a player kicks a football at an angle of 40.0 degrees above the horizontal with an initial speed of 14.0 m/s. Air resistance may be ignored. A second player standing at a distance of 26.0m from the first(in the direction of the kick)...

Homework Statement A baseball is hit at a height of 1m with an initial velocity of 27 m/s at 32 degrees above the horizontal. A field player is located 50m from the home plate along the line of flight. (a) If he runs, is there a chance he could catch it? what's the velocity? Assume his...

Homework Statement A cart is moving horizontally along a straight line with a constant speed of 30m/s. A projectile is to be fired from the moving cart in such a way that it will return to the cart after the cart has moved 80m. At what speed and at what angle to the horizontal must the...