Components Definition and 911 Threads

Say I wanted to set up EFE for the Earth and moon. How do I actually go about filling the stress energy tensor? I'm referencing the wikipedia page. So the time-time should be approximately E/c^2V, so for the Earth moon system ##T_{00} = \frac{3}{4\pi r_E^3}\frac{1}{c^2}(M_Ec^2 + 2/5...

The title, basically. I am aware of the mixing rule for the two-component form: aP = a1z12 + 2z1z2sqrt(a1a2) + a2z22 Where do I find its extension on three or more cases? SVNA does not tell anything about this.

What methods other than Light Dependent Resistor incorporation are there to determine the 'bulb state'? I'm guessing it's going to include the use of another type of optoelectric component? Thanks

I am trying to figure how to get 1. from 2. and vice versa where the e's are bases for the vector space and θ's are bases for the dual vector space. 1. T = Tμνσρ(eμ ⊗ eν ⊗ θσ ⊗ θρ) 2. Tμνσρ = T(θμ,θν,eσ,eρ) My attempt is as follows: 2. into 1. gives T = T(θμ,θν,eσ,eρ)(eμ ⊗ eν ⊗ θσ ⊗ θρ)...

Homework Statement Astone is thrown horizontally with an initial velocity of 5 metres per second. What is the magntude and direction of its velocity 0.2s later? Take the acceleration of free fall to be 9.8 metres per second squared and ignore friction. Homework EquationsThe Attempt at a...

I was working out the components of the Riemann curvature tensor using the Schwarzschild metric a while back just as an exercise (I’m not a student, and Mathematica is expensive, so I don’t have access to any computing programs that can do it for me, and now that I’m thinking about it, does...

Mentor note: Moved from Intro Physics, as this is more of a mathematics question Homework Statement With respect to a prescribed basis... |e 1> |e 2> ...|e n> Any given vector |a> = a1|e1> +a2|e2>+...+a n|e n>, Is uniquely represented by the (order) n-ruble of its components. |a> <--->(...

Hi All, I am evaluating the components of the stress-energy tensor for a (Klein-Gordon) complex scalar field. The ultimate aim is to use these in evolving the scalar field using the Klein-Gordon equations, coupled to Einstein's equations for evolving the geometric part. The tensor is given by...

I'm going through Introduction_to_Tensor_Calculus by Wiskundige_Ingenieurstechnieken. I want to find the covariant and contravariant components of the cylindrical cooridnates. Ingerniurstechnieken sets tangent vectors as basis (E1, E2, E3). He also sets the normal vectors as another basis (E1...

Hi, I was trying to learn fault analysis in three phase system from conceptual point of view. I need your help to clarify few seemingly contradictory points in the following video: 1: At 32: 42, phase to ground fault in introduced. It is said that line voltage Vbc is not affected as is also...

Homework Statement I basically want to find the x and y component of a given magnitude of 1.96 N. I am given some other information such as mass and direction. Since the direction of the vector b is upwards, towards the 90-degree direction, then the y-component will also be equal to the...

Homework Statement This is finding net force on Q3. I was taught by my Physics teacher to always get angle from the Positive side of x-axis (+X-Axis). For example in the above situation, if the angle is -30deg from the +x-axis (assuming the Q3 is the origin), Why is F31 x-component = 140...

Hi, I've been trying to figure out how to get Cauchy Stress Tensor components (~9) from a surface force for a while now. My background in this subject is not too deep, but I'm trying to build a renderer simulation in my free time. I can get surface traction from a Stress Tensor: t =...

1. The problems: The questions are to find the x, y and z components of the equivalent MOMENT at point A in both diagrams. For the green block, I found the y and z components of the equivalent force at point A are -39.04kN and 15.48kN respectively. The Attempt at a Solution For the first...

Say we have a matrix L that maps vector components from an unprimed basis to a rotated primed basis according to the rule x'_{i} = L_{ij} x_{j}. x'_i is the ith component in the primed basis and x_{j} the j th component in the original unprimed basis. Now x'_{i} = \overline{e}'_i. \overline{x} =...

Homework Statement https://imgur.com/gallery/YwCap In side are image of figure, and questions.Homework Equations E = kq/r^2 The Attempt at a Solution So I have an electric field where the y compontents cancel. I have 2Ecos(∂) = E (Electric field at point A) - 2 because there is a top and...

Hi I watched this video of a guy testing a fusebox with a multimeter: if you skip to 6:10 he uses a multimeter on a particular fuse and when putting the black lead on good ground of car and red lead on either side of the fuse he gets the same reading on both sides. He even comments that there...

Homework Statement F =(70N, 57.1∘counterclockwise from positive y−axis)[/B] Find the vector components of F Homework Equations Sin and Cos of the angle[/B]The Attempt at a Solution x is component is 38 and y component is 58 how does the angle being counterclockwise affect my answer? The...

<Moderator's note: Moved from a technical forum and therefore no template.> Homework Statement A proton (q = 1.60 x 10-19) is in a uniform, 0.500 T magnetic field. This proton has velocity components vx = 1.50 x 105, vy = 0, and vz = 2.00 x 105 m/s. Find the force on the proton at t=0. 2...

Hello all! I usually don't like to ask for help... But this is the first week of courses and I'm already stumped on a homework question... 1. Homework Statement So the question states: Find the work by the force F = x^i + xy^j. If the object starts from the origin (0,0), moves along the...

Hello Everybody, A trapper walks a 6.2 km straight-line distance from the cabin to the lake, beginning to the lake has an angle of +45 degrees. Determine the east and north components of her dispacement vector. Work: E component: $6.2\times\cos\left({45^{\circ}}\right)$ = 4.38 N...

Is there a book/report(s) that can shed light on this issue? I am into making custom projects that are powered by engines and one, in particular, I am very interested in making sure I don't get any induced vibrations or oscillations. Suppose I have my engine affixed to a frame and I wish to...

Hello all, I have used Expectation Maximization algorithm to approximate a probability density function (pdf) using a mixture of gaussians. I need to square the pdf corresponding to the mixture of gaussians( it is a weighted sum of normal distributions with non-identical parameters). Rather...

Riley Hobson and Bence define covariant and contravariant bases in the following fashion for a position vector $$\textbf{r}(u_1, u_2, u_3)$$: $$\textbf{e}_i = \frac{\partial \textbf{r}}{\partial u^{i}} $$ And $$ \textbf{e}^i = \nabla u^{i} $$ In the primed...

Apologies if this has answered before:rolleyes: Imagine a cannon ball that's been heated up to a very high temperature, say 1000C so it's still solid. The atoms inside it will be moving, but the ball itself is stationary. Does this mean the atoms in the ball will age slower than the ball...

Hi guys, how do I figure out whether components are in series/parallel with each other just by looking at them? for example, in the circuit on the picture I posted, how do I know which of the resistors are in series/ parallel with each other? I know the definition involves nodes, but in clear...

Homework Statement Given the Speed of vehicle at any instant (say 30 meters/s) and Heading of a vehicle (say 270 degrees ) , how can i find the velocity components which is Vx and Vy . Lemme tell you about the Heading ...This is the convention.. I don;t know if this pic is viewable or...

Homework Statement A ship traveling 55 degrees [W of N] is 65km farther north after 3.0h. What is the ship's velocity. Homework Equations sin, cos, tan? The Attempt at a Solution I know that Vground= Vair + Vwind, and that Vground = Vboat + Vcurrent, but I'm not sure if that is even relevant...

In coordinates given by x^\mu = (ct,x,y,z) the line element is given (ds)^2 = g_{00} (cdt)^2 + 2g_{oi}(cdt\;dx^i) + g_{ij}dx^idx^j, where the g_{\mu\nu} are the components of the metric tensor and latin indices run from 1-3. In the first post-Newtonian approximation the space time metric is...

Homework Statement A 64 microC charge is locate 30 cm to the left of a 16 micro C charge. What is the resultant force on a -12 micro C charge positioned exactly 50 mm below the 16 micro C charge?Homework Equations coulomb law f=k*qq/(r^2),resultant force,resolve into x and y component. The...

Im learning about how to find the x and y components of a vector, but I wanted to verify if I'm on the right track.. Ax=A cos(\theta) <-- solving for x Ay=A sin(\theta) <-- solving for y So if a vector is 9.55m long and points in a -48.0 degree direction. Is it Ay= 9.55 sin(-48.0)=7.3

Homework Statement I'm currently doing a project involving the build of a switching circuit for an SRM. I have to choose a variety of components for each stage of the build. For example, I chose an open collector for the interface device, an optocoupler for the isolation device and an IGBT for...

Hi there, The problem asks me to calculate the Voltage, Current and Power of each component within the circuit. I have already calculated the following: V total = 12 Volts R total = 259.54 Ohm I total = 0.046 Amps I am confused as to how I am supposed to calculate the voltage drop across each...

how does the doppler effect work when the observer and source are not moving in a straight line, what do we take in as the velocity of the observer and the source in the doppler effect equation?

Hello there, suppose we take ##M## to denote the spacetime manifold. Suppose also that ## ds^2 = g_{\mu \nu} dx^\mu dx^\nu##. I have some confusions with regards to the metric and the line elements. My main confusion is at which points in the manifold are ## ds^2## defined? Is it correct that...

Homework Statement Why does a source moving perpendicular to the line between it and the observer produce no doppler effect?Homework Equations The Attempt at a Solution I have heard the the radial velocity of the source relative to the observer must be zero but i don't understand why, if the...

Homework Statement The velocity components in a steady, incompressible, 2-D flow field are u = 2y v = 4x Find the corresponding stream function. Homework Equations u = ∂Ψ/∂y v = -∂Ψ/∂x The Attempt at a Solution I can verify that a stream function exists for this problem because...

Homework Statement Which frequency components are present in the amplitude-modulated (AM) signal A(t)=[1+asin(2πfmt)]A0sin(2πfct), where fm= 3.5 kHz, fc = 540 kHz, and a = 0.1? Homework Equations A(t)=[1+M(t)]A0sin(2πfct), where modulating signal M(t) = sin(2πfm t + ∅), high frequency carrier...

I've thought of a new way (at least I never read it anywhere) of counting the independent components of the Riemann tensor, but I am not sure whether my arguments are valid, so I would like to ask whether my argument is sound or total bonkers. The Riemann tensor gives the deviation of a vector A...

Can someone explain to me why normal Zeeman effect splits spectral line into three components and not into 4, 5 or any other number?

1. The problem statement, all variables, and given/known data Attached is a diagram of what I am trying to solve. I need to calculate the X and Y components for both F1 and F2. The results will then be used in a later problem that I've already solved but I am coming up with an error and I was...

1. For the following, the x-axis is not allowed to be set along the ramp. If a mass, starting from rest, slides along a linear, frictionless incline of length D and then falls a distance h to the ground, will it have an x-component of acceleration? 2. Relevant kinematics formulas? 3. I...

hi; When I study - if we want to connect impedance in the case of: - we connect the R4 and (R1+(R2||R3)) as parallels but when we want the get impedance of C and R of the right: - we connect that as series: Z(of C)+R .. why the different? please help!

Homework Statement A car starts at rest at point A, with a tangential component of acceleration a_t = 0.6m/s^2. Students approximate the acceleration of the car to be 0.6 m/s^2. What are the normal and tangential components of it's speed and acceleration at point B? NOTE : the ends are...

Homework Statement I need to find the tangent of the angle, but I don't think that is the part I'm messing up... Assume the particle doesn't hit the wall. Initial velocity is v. It seems that Vix = 0m/s and ay=0 m/s Homework Equations I thought vfx^2 =vix^2 +2a(xf-xi) f=ma , f=eq The Attempt...

Homework Statement In each of the diagrams (please see attached file (I am sorry for the rotated, the original was in normal form but when uploading it, it was somehow rotated)) and the description of each case below, a particle is moving on a smooth surface, so that the reaction force R acting...

Homework Statement A golf ball is struck at ground level. The speed of the golf ball as a function of the time is shown in the figure, where t = 0 at the instant the ball is struck. The scaling on the vertical axis is set by va= 16 m/s and vb= 29.3 m/s. (a) How far does the golf ball travel...

Given the Fourier conjugates ##\vec{r}## and ##\vec{k}## where ##\vec{r} = [r_1,r_2,r_3]## and ##\vec{k} = [k_1,k_2,k_3]## , are ##r_1## /##k_1##, ##r_2##/##k_2##, ##r_3##/##k_3## also Fourier conjugates, such that: ##\begin{equation} \begin{split} f(\vec{r})&=[f_1(r_1),f_2(r_2),f_3(r_3)] \\...

Hey! :o For the polynomial vector space $\mathbb{R}[x]$ of degree $\leq 3$ we have the following three bases: $$B_1 = \{1 - X^2 + X^3, X - X^2, 1 - X + X^2, 1 - X\} , \\ B_2 = \{1 - X^3, 1 - X^2, 1 - X, 1 + X^2 - X^3\}, \\ B_3 = \{1, X, X^2, X^3\}$$ How can we determine the following...

The component of a one-form W can be represented using the metric as Wβ = gαβUα, where Uα is the component of a vector U, and one can always multiply Wβ by some Vβ to get the inner product between the two vectors U and V. My question is: since the inner product is defined with the two...