Plane Definition and 1000 Threads

I am simulating a radio telescope and confused on what kind of source should I setup to simulate a star. Should it be a TEM00 gaussian beam or simply a plane wave?Cheers, Robin

Definition of a real affine plane is the incidence structure with point set R^2 and line set the union of the vertical lines and the non-trivial lines, with the natural incidence relation. Looking here https://en.wikipedia.org/wiki/Affine_plane it seems an affine plane is the usual Euclidean...

Hello! The following wave solves the 3D wave equation: $$ \frac{\sin\left(k\sqrt{x^2+y^2+\frac{(z-vt)^2}{1-\frac{v^2}{c^2}}}\right)}{\sqrt{x^2+y^2+\frac{(z-vt)^2}{1-\frac{v^2}{c^2}}}}\cos\left(w\frac{t-\frac{vz}{c^2}}{\sqrt{1-\frac{v^2}{c^2}}}\right) $$ This is a propagating standing spherical...

Homework Statement I'm asked to find whether the object is moving or not in this question , i was given the solution like this , i am wondering why the tension from 100kg to the roller(up) and the tension from point B to roller doesn't cancel each other?[/B] Total force acting down the slope...

Consider a system with a mirror axis (bulk projected surface), I want to know the direction of spin polarization on the mirror axis. The result is that the spin is perpendicular to the mirror axis, but I don't understand the reason. If someone have related references, please recommend to me...

So far I have calculated this for a cone, which elegantly results in the conic sections. However, I would like to do this for the other quadric surfaces. Is the calculation for this been published anywhere online?

Hi All, I have a situation were I need to evaluate the heat transfer coefficient of a horizontal surface. The surface has tubes within although I first used "flow across a bank of tubes", this has been untrue due to the air flow coming from above the surface flowing vertically (and...

I want to try and see the intersection between the hyperboloid and the 2-plane giving an ellipse. So far I have the following: I'm going to work with ##AdS_3## for simplicity which is the hyperboloid given by the surface (see eqn 10 in above notes for reason) ##X_0^2-X_1^2-X_2^2+X_3^2=L^2## If...

Homework Statement A projectile is thrown on an inclination plane with incline angle phi with an inital velocity V0 on an angle theta. Find the range of the projectile; treat the hypotenuse of the inclined plane as the x-axis. For what value of initial velocity angle is the range maximum, and...

So, I'm building an rc plane for school that has to theoretically be able to fly on Mars. What differences/limitations are there compared to designing a regular remote controlled plane? This is for a terraformation project, so at this point Mars would have an atmospheric pressure of 50kPa.

What is the "plane of symmetry", "zero velocity wall" and "free surface" terms which I have seen in Polyflow? It says in Vnormal=Fs=0 for plane of symmetry and Vnormal= Vs= 0 for zero velocity Wall. Now I get when Vs=Vn=0 it means that the wall isn't moving and it's in a static state but didnt...

Homework Statement http://tinypic.com/r/qs9q4o/9 http://tinypic.com/r/qs9q4o/9 Verify that the log will move up the ramp under the given conditions Homework EquationsThe Attempt at a Solution m1 = 220 m2 = 130 mu = 0.4 theta = 25 g = 9.81 N = (m1*g)*cos(theta)1) m2g – T = m2a Forces...

1. An object of mass m = 1 kg is initially placed on a frictionless plane, inclined by an angle θ = 30o as indicated below. How long does it take the mass to move the distance of 10 m down the incline?2. I had a question if how I solved this is correct. I got the right answer and I wanted to...

I wish to solve the inverse geodesic problem numerically using http://geographiclib.sourceforge.net/html/classGeographicLib_1_1Geodesic.html#a455300c36e6caa70968115416e1573a4, and to finish off I need to specify the "equatorial radius". I am not too familiar with this, and do not see immediately...

Griffiths' Electrodynamics says that the electric field of a uniformly charged infinite plane, surface charge density sigma, is sigma/2e0. The field of an infinite sheet of charge is said to be sigma/e0, twice that of the plane. What is the supposed difference between the sheet and the plane...

Homework Statement [/B] A ball rests in a trough as shown in figure. Determine the angle of tilt ##\theta## with the horizontal so that the reactive force at B will be one-third at A if all surfaces are perfectly smooth. 2.Relevant equations Application of Lami's theorem and some algebra...

Homework Statement Here the formulation of Dedekind's axioms that I am using:Suppose that line ℓ is partitioned by the two nonempty sets ##M_0## and ##M_1## (i.e., ##\ell = M_0 \cup M_1##) such that every point between two points of ##M_i## is is also in ##M_i##, for ##i = 0,1##. Then there...

Please find the attached (http://s23.postimg.org/ropds44ob/Capture.jpg). I know how to get the shear force for each bolt using bolt analysis. But I don't know how to get the tension/compression force of the bolt when it position is not symmetric. *I already download some excel from internet...

Hello, a dubt arose while doing some exercise. If I have a charge q at a distance d from the above-mentioned plane, i can find the solution to the laplace equations (thanks to the uniqueness theorems) finding a collection of image charges that satisfies the boundary conditions. These conditions...

Homework Statement A 3 m long gate of weight 4 kN per unit width is hinged at O and sits at an angle θ as a function of water height h above the hinge. (A) Using a y-axis measured up from the hinge, derive a general relation between h and θ, with all other variables evaluated in the relation...

Homework Statement A 74.5 kg snowboarder heads down a 16.0° hill that has a height of 78.4 m. If the hill is assumed to be frictionless and there is horizontal wind with a force of 93 N acting against the snowboarder, find the speed of the snowboarder as they reach the bottom of the hill using...

Homework Statement There is a plane flying at 200 km/h and wants to drop a bomb on a car traveling 130 km/h which is 78.0m below the plane. at what angle should the bomb be released? the answer is 45 degrees. Homework Equations sine law: SinA/a= SinB/b cosine law: a^2=b^2+c^2+bcCosA v=d/t...

Homework Statement Solve for the forces P and N acting on an object in equilibrium on an inclined plane. Weight=10N, angle is 30 degrees http://blob:https%3A//www.physicsforums.com/d431a152-5681-411b-ba57-809320539165 Homework Equations Trigonometry, i.e. sin, cos, tan rules. The 'Z' rule...

Homework Statement A real object is put in-between a convex lens (f = 30.0cm) and a plane mirror as shown in the figure below. Two images of the object are observed : a real image 50.0cm to the left of the lens and a virtual image to the right of the lens. The size of the virtual image is 3.00...

1. Introduction Pressure of a fluid exerts thrust on each part of a surface with which the fluid made contact. Each forces distributed over the area have a resultant magnitude and direction that is very crucial. For a horizontal surface, the pressure does not vary over the plane. Thus, the...

Geroch 1968 touches on the Kundt type I and II curvature invariants. If I'm understanding correctly, then type I means curvature polynomials. Type II appears to be something else that I confess I don't understand very well. (I happen to own a copy of the book in which the Kundt paper appeared. I...

Homework Statement A soldier with a machine gun, falling from an airplane gets detached from his parachute. He is able to resist the downward acceleration if he shoots 40 bullets a second at the speed of 500 m/s. If the weight of a bullet is 49 gm, what is the weight of the man with the gun ...

Homework Statement the total force acting downwards the plane = 100(9.81)sin20 + 150= 485.5 N , should I take the tension in B into consideration ? how to get the tension on the rope ? Homework EquationsThe Attempt at a Solution

why do we consider normal line in expressing a plane,say in ##R^3## ,of the form ## ax + by + cz = d ##? What is the logic behind this normal line selection? Plz provide intuitive explanations.Thanks

Homework Statement Find the curve that is the intersection of x-y-z>-10 and x2+y2/4+z2/9=36. Homework EquationsThe Attempt at a Solution The best idea I have is to define x as x=y+z-10 and substitute it into the ellipsoid equation to get a function defined by y and z; the trouble is that...

Homework Statement Write down the equation for a plane wave traveling in perpendicular to the plane x+y+z=constant traveling in the direction of increasing x, y, and z. Homework Equations From the given information how do I determine the unit vector that goes next to E(0)? How do I determine...

Homework Statement A cup is represented by the surface -(z-1)2 + x2 + y2 = 1 and it is on a table represented by the plane z=0 a) find the angle at which the cup intersects the table b) find the equation of the normal line to the cup at the point (0, √2 , 2) c) find the equation the tangent...

This is not a specific problem. It pertains to all the problems I'm working on and only requires that I have one concept explained. If an object is being pulled up a plane by a force parallel to the plane, does the friction work against the parallel component of the gravity or the force pulling...

An airliner crashed in the Sinai peninsula in Egypt carrying 217 passengers (214 Russians and 3 Ukranians). All presumed dead. http://www.bbc.co.uk/news/world-middle-east-34689870 What a tragedy! My thoughts go to their families. ISIS affiliate in Egypt, the so-called Sinai Province, has...

Homework Statement Pco20- Wsin30-100(9.81)(cos20) –Fs = 0 Pcos20 - 1000x9.81xsin30 – 100x9.81xcos20 – 0.2 x ( Wcos20x9.81 + Psin20 ) = 0 Pcos20 – 4905-921.8-1700-0.07P=0 7526.8= 0.869P P= 8661N what's wrong with my working ? the ans given is P=7330N Homework EquationsThe Attempt at a Solution

Homework Statement Homework EquationsThe Attempt at a Solution what is the difference between the form z - zo = fx(x-xo) + fy(y-yo) and: Fx(xo,yo,zo) + Fy(xo,yo,zo) + Fz(xo,yo,zo)=0 ____________________________________________________________________________using the first eq : while...

Hello, Could somebody help me finding the relation between the horizontal force, the weight acting vertically, and the slopes Angle (same for both) that correspond to static equilibrium of the blue ball ? In a first step, I'd like to study this problem without considering friction at all. And...

Homework Statement Hi! I'm not sure the title I gave properly reflects my problem, but I did not know how to describe it in another way: (roughly translated from German) "In three dimensions, we can divide the space in two parts through a plane. In four dimensions, that does not work anymore...

When finding solutions to Maxwells equations we always cosider the case of a plane wave. But are plane waves real/physical solutions we can consider in real life? My guess is not because it is required to propagate infinitely. So why do we use plane waves to solve Maxwell's equations?

Homework Statement Use Green''s Theorem in the plane to check: \oint_C (xy+y^2) \> dx + x^2 \> dy Where C is the closed curveof the region bound between the curve of y=x^2 and the line y=x Homework Equations \oint_C u \> dx + v \> dy = \int \int_A (\partial_x v - \partial_y u) \> dx \> dy...

Homework Statement A particle of mass ##m## rests on a smooth plane. The plane is raised to an inclination ##\theta## at constant rate ##\alpha##. Find the constraint force. Homework EquationsThe Attempt at a Solution ##L=\frac{1}{2}m(\dot{x}^2+\dot{y}^2)-mgy## Lagrangian...

Homework Statement An equiconvex lens having spherical surfaces of radius 10cm, a central thickness of 2cm, and a refractive index of 1.61 is situated between air and water (n=1.33). An object 5cm high is placed 60cm in front of the lens surface. Find the cardinal points for the lens and the...

Homework Statement A block of mass m1 = 3.70 kg on a frictionless inclined plane of angle 30.0° is connected by a cord over a massless, frictionless pulley to a second block of mass m2= 2.30 kg hanging vertically. What are (a) the magnitude of the acceleration of each block and (b) the...

Homework Statement An infinite plane of charge has surface charge density 6.8 µC/m2. How far apart are the equipotential surfaces whose potentials differ by 100 V? In mm Homework Equations E=σ/(2ε0) The Attempt at a Solution So first I solved for E= 6.8e-6/(2*8.85e-12) = 384170.791 then...

A solid sphere and a hollow one of same mass and radii are rolled down a rough inclined plane. Which of the following is true? (A) solid sphere reaches bottom with greater speed. (B) solid sphere reaches the bottom with greater kinetic energy. ( I know that option A is correct.Thus I felt that...

A uniformly charged disk has radius R. It was a charge density and is located above the conducting plane at a distance a. The disk is parallel to the conducting plane. Find the electrostatic potential at (0,0,z) in the region above the plane. The conducting plane is grounded

Hello! I just need someone to check my work here. I already turned in the homework with my hunch, but now I just want to check my work because it is killing me not knowing 100% :) I am having strong conflicting thoughts on particular parts and thought I'd post it here for clarification. I will...

Suppose we have an inclined plane and 2 wheels. Both wheels have the same mass M but different radius R. So the only difference is that one is bigger than another. We put both wheels on the top of the inclined plane. They are in the same position, and then we let them go. I know that the wheel...

Homework Statement Line perpendicular to a plane Plane: z(x,y)= 0.882531*x-0.346494*y+0.383108 P1(0.5;0.1;Z) P2(0.4;0.15;Z) Homework EquationsThe Attempt at a Solution z(0.5,0.1) = 0.7897 z(0.4,0.15) = 0.68414 vector n=ai+bj+ck vector P2P1 = (0.5-0.4)i + (0.1-0.15)j +(0.7897-0.68414)k...

Homework Statement Find the area of the region in the plane where, r2sin(2theta) >2(sq.root3) , r^2 < 4 Homework EquationsThe Attempt at a Solution To try to visualize the problem a little better I converted from r2sin(2theta) to 2xy. However I'm confused after this, since I don't know what...