2d Definition and 1000 Threads

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...

Homework Statement A particle starts from rest at (r0) = 9m j-hat and moves in the xy-plane with the velocity shown in the figure . The particle passes through a wire hoop located at (r1)=20m i-hat, then continues onward...

Homework Statement You are designing a missile defense system that will shoot down incoming missiles that pass over a perimeter defense post. The set-up is shown below. An incoming missile passes directly above the defense base. Radar at the base can measure the height, h, and speed, v1, of...

Hello, in order to numerically solve a physics problem I think I need to add 2 (infinitesimal) rotations of one and the same segment each around a different point in 2D space in one iteration of numeric approximization. How does this addition work out? Is it the sum of the vectors connecting...

Homework Statement hello everybody, I am trying to obtain the flow velocity in two dimensions u(x,y) for the case of a flow past a circle. The equations to solve are: \vec{\nabla} p = \mu \vec{\nabla}^2 u \vec{\nabla} \cdot \vec{u} = 0 I am very blocked at the moment and I...

Came across this one in my freshman physics book: A particle of mass 1m is traveling along the x-axis at velocity V1. It collides elastically with a second particle of mass 3m traveling at velocity V2. The first particle (1m) moves off at 0.92m/s at 48º to the x-axic. The second particle (3m)...

Hello, I am using Maxwell SV to model the magnetic field inside a solenoid coil. I am currently using the eddy current solver as I have an AC source (167 kHz). When I map the H field in the post processor is the software computing induced magnetic field due to eddy currents in the conductor...

Homework Statement Two balls od the same masses collide, the first one is moving with the velocity v_1, the second is stationary. The angle between them is given by the statement: "the direction of the velocity of the first ball forms an angle \alpha=30^\circ with the plane of osculation of...

Homework Statement OK, I'm posting to clarify if my answer is correct. 1. An airplane is flying with a velocity of 90.0 m/s at an angle of 23.0m\s above the horizontal. When the plane is a distance 115 m directly above an observer that is standing on level ground, a suitcase drops out of the...

Homework Statement The figure shows the circular wave fronts emitted by two wave sources. Make a table with rows labeled P, Q, and R and columns labeled r1, r2, \Deltar, and C/D. Fill in the table for points P, Q, and R, giving the distances as multiples of \lambda and indicating, with a...

Homework Statement The astronaut orbiting the Earth in Figure P4.32 is preparing to dock with a Westar VI satellite. The satellite is in a circular orbit 700 km above the Earth's surface, where the free-fall acceleration is 8.12 m/s2. Take the radius of the Earth as 6400 km. 2. Relevant...

Hey. I want to derive the conductivity of graphene. I'm looking for a formula of the sort: J = \frac{e}{\hbar} n \frac{dE}{dk} D(E) \Delta E where \frac{1}{\hbar} \frac{dE}{dk} is the electron velocity, D(E) = \frac{dN}{dE} is the density of states, \Delta E might be the applied voltage...

A two-dimensional harmonic oscillator is associated with the group Su(2). What is that association? Solutions to the Dirac equation require a pair of spinors at each point? Can we think think of spacetime as having pairs of 2D harmonic oscillators at each point? Thanks for any help.

Homework Statement A Nordic jumper goes off a ski jump at an angle of 10.0 degrees below the horizontal, traveling 108 meters horizontally and 55.0 meters vertically before landing. (a) ignoring friction and aerodynamic effects, calculate the speed needed by the skier on leaving the ramp...

Please Help! Motion in 2D Question Homework Statement A student stands at the edge of a cliff and throws a stone horizontally over the edge with a speed of 15.0 m/s. The cliff is h = 26.0 m above a flat horizontal beach, as shown in Figure P3.24. Homework Equations How long after...

I have asked this question before in another section of the forum but I still don’t have an answer so I thought I would try here. Ok…here goes.. In three dimensions, Poissons equation can be used to model an electrostatic problem in which there is a single point charge at the origin. The...

Hello! Since this is my first post I would like to say I am happy that I joined PF and I will try to contribute as much as I can to this great community. So let's get down to the gist of the problem. You are standing 4m from a vertical wall and 0.8m from the ground. You have a bouncy ball that...

I am interested in solving the null geodesic between two points in the presence of a gravitational mass, assuming that everything takes place in 2 dimensions (i.e., no Z coordinate). The following is known: -x and y coordinates of first point -x and y coordinates of second point -x and y...

Homework Statement Need to prove that a slider crank mechanism fits the Grueblers eqaution, already done for a four bar mechanism no problem, however having some serious problems with the slider crank. If l is the number of links and j is the number of joints Homework Equations Grueblers...

Homework Statement The speed limit in a school zone is 40 km/h (about 25 mi/h). A driver sees a child run onto the road 13 m ahead of his car. He applies the breaks, and the car decelerates at a uniform rate of 8.0 m/s^2. If the driver's reaction time is 0.25 s, will the car stop before...

When one compares the fundamental solution for Laplace's Equation one might note that in 2 dimensions this solution becomes unbounded as r goes to infinity while in 3 dimensions the solution goes to zero as r goes to infinity. Now I understand both mathematical derivations so my question is...

Hi all, I like working with computer graphics so I often work between 2D and 3D computer simulations. For example let’s say you had a square in a XY coordinate system and you wanted to move it to an XYZ coordinate system. Placing it in directly would mean that when viewed along the Z...

relation of fermi energy in 3D is E=h(cut square)k(square)/2m, if i want a relation of fermi energy in 2D,what should i do?

Homework Statement Calculate the speed of the minute hand on the clock (I solved with the assumption of the minute hand being the radius) with the length of 25 cm. How many degrees did the minute hand move through from 12" point to 2" point? What is the average acceleration...

I'm looking, as an observer, at imaging accretion discs and tori around Kerr black holes. The image of the disc/torus is projected onto a 2D grid (a CCD if you like) so all lensing effects etc. are implicit. Basically, I can plot the image after determining the (x,y) coordinates in the 2D grid...

Hi guys, I know it’s not triangle, rectangle, square, or circle, but, can anyone tell me what these three two dimensional plane name in english is (images are attached)? Thank you very much in advance Huygen

Hi, I have created data files by compiling and running a c++ code. Now I need to open and store the contents of these files in Fortran 77 variables. But I am not able to do this. The read command does not return the values stored in the file. The files are having some 2003 lines and 53...

Hi everybody, I am currently working on a small computer programming project, and was wondering if you could give me hand. Say I have two simple, identical balls moving in different speeds and angles towards each other. They hit each other elastically, and weigh exactly the same. The...

Homework Statement A 1.2kg mass moving 2.4m/s [East] has an elastic collision with a 2.4kg mass moving 1.8m/s [North]. What are the final velocities? ------------------------------------- I know that I need Ek before and after the collision, but I'm not sure how to calculate it for this...