Terms Definition and 1000 Threads

What is the name for the "stuff" (neither matter nor neutrons) at the heart of a black hole?

So according to classical electrodynamics, an electron would produce an electric field that is a physical entity in and of itself. This field has momentum so when a test charge is placed within this vicinity, it would be affected by the field itself, not the electron. But what about the QFT way...

can anybody please tell me terminology of flight controller and it's specifications. Also, how these specs matter, like what is the effect of increase in Magintude or Frequency of different parameters which will help me buy a flight controller for a quadcopter. I want to build a FPV for racing.

The sum of the $k$ th power of n variables $\sum_{i=1}^{i=n} x_i^k$ is a symmetric polynomial, so it can be written as a sum of the elementary symmetric polynomials. I do know about the Newton's identities, but just with the algorithm of proving the symmetric function theorem, what should we do...

The Weinberg angle ##\Theta_{W}## is commonly expressed as $$\cos\Theta_{W} = M_{W}/M_{Z}.$$ Can the Weinberg angle ##\Theta_{W}## be expressed in terms of the Higgs mass and the mass of the W boson as $$\sin^{2}\Theta_{W}= m_{H}/M_{W}?$$

I would like to consider the interaction terms in the Standard Model which allow the following decay process: The only interaction terms in the Standard Model which allow this decay process are contained in the charged current interactions: $$\mathcal{L}_{cc} =...

I am trying to figure out the interaction terms in the Lagrangian which are linear in the top quark.I find that these terms can only be found in the charged-current interaction since the neutral-current interaction and the gluon-fermion couplings are quadratic in the top quark. Now, I find two...

Hey, I'm writing my CV in English right now, and because my native language is Portuguese, I got stuck on some specific terms. Two to be fair. 1) Here in my university we have a scholarship that lasts one semester (our academic year is divided into two semesters) which is given to undergraduate...

Hi. I want to solve \frac{\partial x^{\nu}}{\partial x^{\mu} + \xi ^{\mu}}, knowing that \frac{\partial x^{\nu}}{\partial x^{\mu}} = \delta ^{\nu}_{\mu}. How can I do this?

I was given a function that is periodic about 2π and I need to plot it. I was wondering if there is a way to input a value and have mathematica generate a new graph with the number of iterations. The function is: $$\sum_{n=1}^{N}\frac{sin(nx)}{n}$$ where n is an odd integer. I guess a better...

Homework Statement Express volume expansivity (B) in terms of density (ρ) and its partial derivatives Homework Equations B = (1/V) (dV/dT) V = m/ρ The Attempt at a Solution I have only managed to substitute m/ρ into the expansivity equation. Don't really understand how to manipulate the...

In the electroweak sector, we define the left-handed Weyl fields ##l## and ##\bar{e}## in the representations ##(2,-1/2)## and ##(1,+1)## of ##SU(2) \times U(1)##. Here, ##l## is an ##SU(2)## doublet: ##l = \begin{pmatrix} \nu\\ e \end{pmatrix}.## The Yukawa coupling in the electroweak sector...

I would like to ask about some terms of control engineering. What are other common expressions for "moving a pickoff point" which can be used as" moving a pickoff point behind of a block" or as "moving a pickoff point ahead of block." Source:Self-made Thank you.

$a_1,a_2,...,a_{100}\in \begin{Bmatrix} 1,2,3,-----,100 \end{Bmatrix}$ $S=\dfrac{1}{\sqrt{a_1}}+\dfrac{1}{\sqrt{a_2}}+\cdots+\dfrac{1}{\sqrt{a_{100}}}=12.5$. Prove that at least two of the numbers are equal

Evaluate \tan^4 10^\circ+\tan^4 50^\circ+\tan^4 70^\circ without the help of a calculator.

I am trying to make sense of a Russian author’s use of terms (I have to translate his article). I have three questions, but please don't think you need to answer all three before answering. Thanks for any insights! [1] He uses the term “probability density distribution” ρ(ξ) of a stationary...

The natural numbers $a_1,\,a_2,\,\cdots,\,a_{100}$ are such that $\dfrac{1}{\sqrt{a_1}}+\dfrac{1}{\sqrt{a_1}}+\cdots+\dfrac{1}{\sqrt{a_1}}=20$. Prove that at least two of the numbers are equal.

First term of the progression is 3 & the common difference is 4 Find the sum of the first 20 terms of the progression that is obtained by removing the terms in the even positions of the given progressions, such as the second term,fourh term, sixth term. Formula preferences For the sum of an...

Homework Statement This is not a particular problem but a generic one. If one has acceleration stated in terms of velocity (or position) such as a=v, how do we convert these values into time? Homework Equations ads=vdv ad(theta)=wdw And of course, the usual time-based derivative relations...

Hi, The Tresca Critrion is given in the form of non continuous equations: Max(½|σ1-σ2|,½|σ2-σ3|,½|σ3-σ1|) = k How did they come up with the invarient equation f(J2,θ) = 2√J2 * sin(θ+⅓π)-2k, θ from (0 to 60)

Homework Statement If the average (arithmetic mean) of 3a and 4b is less than 50, and a is twice b, what is the largest possible integer value of a? Homework Equations Avg of two variables is: (a+b)/2 The Attempt at a Solution (3a + 4b)/2 < 50 3a + 4b <100 Now try out values such a = 2b I) a=...

In our section on path independence, we were asked to find the potential function given a vector field. Our teacher says to use only line integrals to find the potential function, and not any other method. Like if we have ##F=\left< M,N,P \right> ## The first step is to determine if the domain...

Homework Statement I am trying to express ##T(\phi(x1)\Phi(x2)\phi(x3)\Phi(x4)\Phi(x5)\Phi(x6))## in terms of the Feynman propagators ##G_F^{\phi}(x-y)## and ##G_F^{\Phi}(x-y)## where ##G_F^{\phi}(x-y) =\int \frac{d^{4}k}{(2\pi)^{4}}e^{ik(x-y)} \frac{ih}{-k.k - m^2 -i\epsilon} ## and...

I have the expression, A(Bx + 1) = C*d^(2x) where A,B,C and d are constants. How to arrive at an expression for x in terms of A,B,C and d? I have tried doing this: Log [A(Bx + 1)/C] = Log [d^(2x)] 2xLog(d) = Log[A(Bx + 1)/C] but I'm unable to arrive at an explicit expression of x in terms...

Homework Statement Given two inductors, connected in parallel connected to a battery, why do the following emf relations hold? $$\mathcal{E}_1 = - N_2 A \frac{d B}{d t} = -M\frac{d I_1}{d t } \\ \mathcal{E}_2 = -L_2 \frac{dI_2}{dt}- M \frac{dI_1}{dt}$$ See attachment ! Homework Equations...

$\textsf{a. Find the first three nonzero terms of the Taylor series $a=\frac{3\pi}{4}$}$ \begin{align} \displaystyle f^0(x)&=\sin{x} &\therefore \ \ f^0(a)&=\sin{x} \\ f^1(x)&=\cos{x} &\therefore \ \ f^1(a)&= -\frac{\sqrt{2}}{2}\\ f^2(x)&=- \sin{x}&\therefore \ \ f^2(a)&=\frac{\sqrt{2}}{2} \\...

$\textsf{a. Find the first four nonzero terms of the Taylor series $a=1$}$ \begin{align} \displaystyle f^0(x)&=6^{x} &\therefore \ \ f^0(a)&= 6 \\ f^1(x)&=6^{x}\ln(6) &\therefore \ \ f^1(a)&= 6\ln(6) \\ f^2(x)&={6^{x}\ln(6)^2} &\therefore \ \ f^2(a)&= {12\ln(6)} \\ f^3(x)&={6^{x}\ln(6)^3}...

$\tiny{206.11.3.39}$ $\textsf{a. Find the first four nonzero terms of the Taylor series $a=0$}$ \begin{align} \displaystyle f^0(x)&=(1+x)^{-2} &\therefore \ \ f^0(a)&= 1 \\ f^1(x)&=\frac{-2}{(x+1)^3} &\therefore \ \ f^1(a)&= -2 \\ f^2(x)&=\frac{6}{(x+1)^4} &\therefore \ \ f^2(a)&= 6 \\...

$\textsf{a. Find the first four nozero terms of the Maciaurin series for the given function} \\$ \begin{align} a&=0 \\ f(x)&=(-5+x^2)^{-1} \\ \\ f^0(x)&=(-5+x^2)^{-1}\therefore f^0(a) = 1 \\ f^1(x)&=\frac{-2x}{(x^2-5)^2} \therefore f^1(a) = 0 \\ f^2(x)&=\frac{2(3x^3+5)}{(x^2-5)^3} \therefore...

I've tried repeatedly to get clear, succinct definitions of the following terms over and over again, but invariably the definitions provided clash, and I'd like to put an end to that. The terms I am trying to define clearly are: - Relation - Definition (Mathematical definition) - Function -...

Homework Statement A particle in central force field has the orbit r=cφ^2, c is a constant. Find the potential energy, Find r and phi in terms of t. I get how to find the potential energy and found it to be U=-l^2/mu (2c/r^3+l/2r^2) l is angular momentum and mu is the reduced mass But how do I...

Homework Statement I am very rusty on my mathematics and I am wondering if there is a way to express Rs in terms of r1 and r2. The positions of the bodies are all relative to the origin 0 (C.o.M between m1 and m2). Basically I'm trying to express the two vectors coming from m3 in terms of the...

Homework Statement The circuit of FIGURE 2 is known as a transimpedance circuit used for the measurement of very small currents. Derive the relationship between the output voltage V and the input current I; i.e. if V = kI find k in terms of R1, R2 and Rf. Homework EquationsThe Attempt at a...

I'm trying to understand the physics of reflection to better draw objects. Normally, you see the reflection of a light source on metallic surfaces where the angle of incidence can equal the angle of reflection. This should reflect an image of the source that is approximately equal in size to how...

Hi. Is the Maxwell equation $$\nabla\cdot\vec{E}=\frac{\rho}{\varepsilon_0}$$ even true in the stronger form $$\frac{\partial E_i}{\partial x_i}=\frac{\rho}{3\cdot\varepsilon_0}\enspace ?$$ I guess not, since I haven't found a source suggesting this. But shouldn't the isotropic electric field...

Homework Statement Why can't we have 4s^2 3S1 calcium? I've looked up a table of terms and this is never given, so I guess we can't have it. Why can't the spins of each of the outer electrons add to give S = 1, J = 1, and a degeneracy of 3? I guess the answer must be pretty basic since nobody...

Write out the first four terms of the sequence defined by the recursion n_(n+1)=n_1+1,n_1=−1 $\text{Write out the first four terms of the sequence defined by the recursion}$ $$\displaystyle a_{n+1}=a_1+1,a_1=−1$$. $\text{so then}$ $$\displaystyle a_{0+1}=-1+0=-1$$ $\text{stuck!}$

Since there is an energy operator interms of t and a momentum operator interms of x as expected.For energy there is a hamiltanion operator interms of t which is unexpected for me.Similarly whether there is any operator interms of t for momentum also?

If $log_a 2 = P $ & $ log_a 3 = q$ find $log_a 72 $ in terms of $p$ & $q $ I'm not sure on how to begin this may be convert the logarithms to decimals :confused: Many Thanks :)

I'm having trouble in expressing the shaded region in set notation (Thinking) Many Thanks :)

Problem O is the center of the circle and AB is the diameter of this circle , C & D are points on this circle , If $\angle CDB=x^\circ$ ,State the following angles in terms of $x$ $\angle CAB$ $\angle CBA$ Workings & what is known $OC=OB=OA$ radii of the same circle $\therefore \angle...

:D I have trouble in determining the ratio of the area of $\triangle PST$ in terms of $\triangle PQR$ In the triangle PQR $QT=TR$, $PS=1 cm$ , $SQ=2 cm$ , How should I be writing the area of $\triangle PST$ in terms of $\triangle PQR $ What is known by me : Since...

Mt. Vesuvius in Pompeii was a conic volcano with a height from its base 7950 feet and a base radius of 2300 feet. In 79 AD, the volcano erupted, reducing its height to 4200 feet . Find the volume of the volcano after 79 AD in terms of pi. WORK: Volume of Volcano(Before 79AD)= \pi *r^2*h/3...

I've read explanations on the internet that the product of two angles is not something fundamentally important. So, the sin of product of two angles cannot be expressed in terms of sin of individual angles. But in calculus, we often come across these functions, we deal with functions involving...

Homework Statement The coefficient, β, of thermal expansion of a liquid relates the change in the volume V (in m3) of a fixed quantity of a liquid to an increase in its temperature T (in °C): dV = βV dT (a) Let ρ be the density (in kg/m3) of water as a function of temperature. (For a mass m of...

In chemistry, chemical bonding is a very important topic. What I can't really understand is the interrelation of different theories which explains the same kind of thing, like for structure of any compound there are theories like Valence bond theory or VSEPR or molecular orbital theory. I am...

Homework Statement A particle is attached by means of a light inextensible string to a point 0.4 m above a smooth horizontal table. The particle moves on the table in a circle of radius 0.3 m with angular velocity ω. Find the reaction on the particle in terms of ω. Hence find the maximum...

In simple addition we learned to add all the numbers together to get a sum. In algebra, numbers are sometimes attached to variables and we need to make sure ...

We've learned about order of operations and combining like terms. Let's layer the distributive property on top of this. Practice this lesson yourself on Khan...

This example of combining like terms in an expression gets a little hairy. Listen closely. Practice this lesson yourself on KhanAcademy.org right now: https:...