2d Definition and 1000 Threads

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...

Homework Statement In a large water tank experiment, water waves are generated with straight, parallel wave fronts, 3.00 m apart. The wave fronts pass through two openings 5.00 m apart in a long board. The end of the tank is 3.00 m beyond the board. Where would you stand, relative to the...

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...

Is it possible for me to use a Voronoi diagram - or some other algorithm - to represent a point in an multidimensional space (between 5 and 10 dimensions) in a 2D geometrical shape? (And more interestingly, in a geometrical shape that is a) fairly small, and b) looks aesthetic. I have a...

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...

when calculating the frequencies of 1\H's oscillation using De Haas-van Alphen, we need to find the extremal cross-section of the fermi surface perpendicular to the magnetic field direction. in 3d i can understand this. but when talking about a 2d lattice where the magnetic field is...

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 A person is standing on a cliff that is 10m tall, the boy is 2m back from the ledge of the cliff. He shoots an arrow at a 45 degree angle. Initial velocity is 5 m/s. I need to find max height when the arrow will reach the height. How far the arrow went in the X...

Hi there I'm thinking about using the rotation invarient moments by Hu/Flusser (http://en.wikipedia.org/wiki/Image_moment#Rotation_invariant_moments). I'm a physicist by trade, with exceptionally poor math..! I'm not comfortable with exactly what these invariants are. The wikipedia link...

Homework Statement Hi all. This isn't quite a homework problem but I figured this is the best place to post it. I was working through the derivation of Pressure (P = (1/3)*n*m*v^2 bar) via kinetic theory in Sears + Salinger's Thermodynamics / Kinetic Theory / Statistical Thermodynamics...

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...

hellow everybody i have a problem in styding the critical bihaviour of the tow dimensional ising model when i use periodiques boundary conditions i found that the fixed point for this case is the PRG equation that mean the following recursion relation...

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...

Homework Statement A dart player throws a dart horizontally at a speed of 11.8 m/s. The dart hits the board 0.31 m below the height from which it was thrown. How far away is the player from the board? x y vi= 11.8 vi= 0 a=0 a= 9.81...

Homework Statement A bird watcher meanders through the woods, walking 0.30 km due east, 0.65 km due south, and 2.25 km in a direction 37.0° north of west. The time required for this trip is 3.00 h. Determine the magnitude and direction (relative to due west) of the bird watcher's (a)...

In the article "The Lattice Theory of Quark Confinement", by Claudio Rebbi (Scientific American) there is a graphic representing the chromoelectric field. The caption reads: "Chromoelectric field is a gauge field similar in principle to the electromagnetic field but more complicated...

Homework Statement From the top of a tall building, a gun is fired. The bullet leaves the gun at a speed of 340 m/s, parallel to the ground. As the drawing shows, the bullet puts a hole in a window of another building and hits the wall that faces the window. (y = 0.48 m, and x = 6.0 m.) Using...

Homework Statement A cork shoots out of a champagne bottle at an angle of 38.0 degrees above the horizontal. If the cork travels a horizontal distance of 1.4m in 1.15 seconds what was the initial speed? Homework Equations x(t)=x2+vit+.5at2 The Attempt at a Solution 1.4=0+1.15x...

Homework Statement Stationary ball is placed 20 degrees to the right of the moving ball's trajectory. Both balls are of same weight. Collision occurs and balls part at 90 degree angle. We measured it and it was 90 degrees on two occasions. Explain why it is 90. Homework Equations...

Homework Statement Two forces, vector F 1 = (3 i - 2 j) N and vector F 2 = (4 i - 7 j) N, act on a particle of mass 1.70 kg that is initially at rest at coordinates (-1.70 m, +4.25 m). i know that the components of the velocity at 9.4 seconds are (38.7i - 49.7647j)m/s i also know that...

This is an assignment question, so I'm not looking for the answer but perhaps just a nudge in the right direction. Homework Statement The captain of a plane wishes to proceed due west. The cruising speed of the plane is 260 m/s relative to the air. A weather report indicates that a...

Homework Statement A rectangular plate is acted upon by the force and couple shown. This system is to be replaced with a single equivalent force. a) for a(alpha)=40 degrees, specify the magnitude and the line of action of the equivalent force. b)Specify the value of a(alpha) if the line of...

Homework Statement A ball player hits a home run, and the baseball just clears a wall 8.00 m high located 122.5 m from home plate. The ball is hit at an angle of 39.9◦ to the horizontal, and air resistance is negligible. Assume the ball is hit at a height of 1.2 m above the ground...

Homework Statement In a scene in an action movie, a stunt man jumps from the top of one building to the top of another building 4.8 m away. After a running start, he leaps at an angle of 11◦ with respect to the flat roof while traveling at a speed of 5.4 m/s. The acceleration of...

Hi all, I'm getting stuck on this problem. Homework Statement I am asked to show that that the open ball in the plane {|x|} < 1} can be written as a countable union of rectangles [a_1, a_2] x [b_1,b_2], but the closed ball in the plane {|x| <= 1} cannot be written as a countable union of...

Homework Statement A batter hits a baseball at a speed of 45 m/sec at an angle of 50° above the horizontal. The right fielder, who is standing 300 m away from the batter, begins to run when he sees the bat hit the ball. If the fielder runs at a constant speed, what speed does he need to run...

In my engineering class we are learning about finding the true length of a line. I don't understand it at all. We basically work with 2D views of a line in either the profile, front, or horizontal view. I don't understand how to get from one view to the next. Does anyone know of any good...

Homework Statement An object is shot from the origin with a velocity of 40.0 m/s at an angle of 55.0 degrees above the horizontal. What is the location of the object 3.00 seconds later? Homework Equations All 2D motion equations - too many to list Ex: V_x = v_0x + a_x t V_y...

Homework Statement A 4.00-kg cannon ball is flying at 18.5 m/s [0º] when it explodes into two fragments. One 2.37-kg fragment (A) goes off at 19.7 m/s [325º]. What will be the velocity of the second fragment (B) immediately after the explosion? Assume that no mass is lost during the explosion...

2D or 3D vector problem?? Homework Statement Find the vector product of Vector A cross Vector B(expressed in unit vectors) of the two vectors. What is the magnitude of the vector product? Homework Equations Vector A= 5.00i + 2.00j Vector B= 3.00i - 1.00j The Attempt at a...

[b]1. A delivery truck travels 10 km north, 18 km east, and 29 km south. a) What is its final displacement in km from the origin. b) What is the angle in degree of the final displacement relative to the east. [b]2. I used the pythagorean theorem to obtain the final displacement from the...

A projectile is fired straight upward at 135 m/s. How fast is it moving at the instant it reaches the top of its trajectory? My answer: 0 m/s Suppose instead it were fired upward at 35°. What would be its speed at the top of its trajectory? m/s I do not know how to approach...

vectors and motion in 2D (physics 1111 problem!) The bacterium Escherichia coli (or E. coli) is a single-celled organism that lives in the gut of healthy humans and animals. When grown in a uniform medium rich in salts and amino acids, these bacteria swim along zig-zag paths at a constant speed...

Homework Statement A stuntman is jumping from building A to building B. His flight lasts 1s. He leaves point A with a speed of Vo at an angle of 30 degrees above horizontal. Building B is .9m shorter than building A. What horizontal distance was covered by the stuntman given he makes it to the...

Homework Statement A stuntman is jumping from building A to building B. His flight lasts 1s. He leaves point A with a speed of Vo at an angle of 30 degrees above horizontal. Building B is .9m shorter than building A. What horizontal distance was covered by the stuntman given he makes it to the...