Point Definition and 1000 Threads

I'm not sure how to proceed with this, but here are my findings/hypothesis: First we find the electric field contributed by the plate with ##E=\frac{\lambda}{2\pi r\epsilon_{0}}## where r=2? After finding out the electric field, is it safe to assume I can find the acceleration of the point...

Okay, I am not even sure how to startr with this question. But here's my theory: First I will need to the electric field produced by the ring using the formula: ##E = k\frac{\lambda a}{(x^2+a^2)^{3/2}}## After finding out electric field produced by ring, am I supposed to find out the...

This is the figure for the problem: 1.) Solved for initial total EPE of the system EPE system = (kq2q3/a) + (kq2q1/b) + (kq1q3/√a^2 + b^2) 2.) Solved for final EPE of the system negating q1 as if it were off to infinity EPE system final = (kq2q3/a) 3.) Plugged values into equation W =...

Dear All, Please help me. A computer company plans to produce 30000 computer next year. They will sell for \$700 each. The fixed cost of operation care \$5000000 total variable cost are \$6000000. What is the break even point?

Hello.. I am confused in two questions. First one is i am designing 1 pin shaped which can mould the free form surface. i am confused in different type of shapes pin like circle, square, triangle..etc.. My question is if i am moulding a free form surface by these shape of pins which shape will...

Here is my work done for this problem, along with a diagram of the situation. I'm not worried so much about the arithmetic because our tests are only 50 min long so the problems they give us do not require heavy integration or calculus, but you need to know what goes where in the formula. That...

Nowadays a lot of people like to fashion themselves in a way that is less traditional. You might see men wear make up or men and women coloring their hair some color that isn't naturally possible. Since society is so free, even among serious scholars (as I see in my department), what is the...

Hi! I need help with this problem. I tried to solve it like this: First I calculated the electric field of each ring: Thus the electric field at a point that is at a distance z from the ring is ##E=\frac{Qz}{4\pi\epsilon_0(z^2+r^2)^{3/2}}##, Thuss for the upper ring, the electric field would be...

Hello World, I have understood the following: in SR, time intervals and space intervals (distances, lengths) are relative and inertial reference frame dependent. Space and time is not absolute anymore. However, acceleration is still absolute: different inertial frames see the same acceleration...

Hoping for feedback regarding engineered conductors that has high melting points (>4000C). Does anyone perhaps know of such metallic alloys or conductive material? (please, no 2D/1D materials -- exotic materials/alloys are OK, just has to be able to be made in bulk!) Thank you!

Say you have some n dimensional manifold embedded in a higher space. what is the best way to describe or define a point on a manifold with or without coordinates. How could I do this either intrinsically or using the embedded space. Would you use the tangent space somehow using basis vectors?

If I'm computing $$\mathcal{T} \langle 0 | \prod_i^Ne^{\imath \beta_i \phi(x_i)} | 0\rangle $$ where the contractions at the same spacetime point are ignored, can I simply insert a complete set of states (product now outside of expression) between each exponential to give $$\mathcal{T}...

I have the following code in Octave: h = [29.3 25.3 19.7 16.0 10.9]; v = [0.53 0.47 0.37 0.29 0.21]; plot(h,v,'obk') hold on p = polyfit(h,v,1); y = polyval(p,h); plot(h,y,'-bk') And I get a good graph: I can extrapolate the best fit line using the following code: x = -1:0.01:11; >> y =...

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We want to calculate the ao/a(teq) of the equilibrium point between ρm and ρr (ρm= ρr ) My book solves it this way; ρm(t) / ρr(t)= a(t) ⇒ ⇒ (ρm/ ρr)teq =1 = = (ρm/ ρr)o * a(teq)/ ao I don't understand the a(teq)/ ao part. If ρm(t)= ρο/αo3 and ρr(t)= ρο/αo4 then it should be ρm(t)/ ρr(t) =...

Let us suppose we have a line ##l_1 = ax + by + c = 0## and we have a point P, ##P(x_p, y_p)## that is outside of this line. If we draw a perpendicular line from point ##P## to a point on the ##l_1##. What would be the coordinates of this point ? I know there are many ways to do it. But I am...

I am interested in a water heater found in consumer market, however, it's made of kind of plastic, I often "feel" that there must be some problem heating up something like plastic. I understand that it should be tested and safe before putting into the market, however, I still wish to know -...

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Hello As the angle of attack of an airfoil changes, the lift force ##L## changes both in magnitude and position (not in direction, always upward). The force location is a point called the center of pressure ##x_{cp}##. It is possible to transfer the force to any another different point along...

There are two related Lemmas in Schaum's Outline of Group Theory, Chapter 4 that seem excessively convoluted. Either I am missing something or they can be made much simpler and clearer. Lemma 4.2: If H is a subgroup of G and {\rm{X}} \subseteq {\rm{H}} then {\rm{H}} \supseteq \left\{...

Hi, I have a device I'm suspending from a chain and the chain attaches to the body with a pin. I'm curious how you would calculate how much weight a pin like that could take before failing. There is a block on the body and a bar on the end of the chain that slots into the block and the pin goes...

X-1 > 0 x>1 $x^2$ - 2x >0 X>2 For 0<x<1 f(x) = -x +1 + -$x^2 $ +2x For 1<x<2 f(x) = x -1 - $x^2 $ + 2x Find each of the equation the critical point By using f'(x) = 0 And decide which is max and min I get x = 1/2 and x = 3/2 But it's wrong Why?

Hi, In the Schrodinger's Cat thought experiment, we say that the cat is in a superposition of states of being either dead or alive. But isn't that opinion biased from being outside of the system? From the cat's point of view, it is either dead or alive but never both. The same argument can be...

I've taken on a new job recently where I'm having to maintain an existing application that generates a points profile to drive a CNC machine and part of it projects points from an axial plane (which represents the machine's working axis) onto another plane which (I think) acts as as a...

Talking about the Jupiter Lagrange points at 60 degrees only. Hard to imagine a scenario where an asteroid comes from outside or inside the orbit of Jupiter and stops at a Lagrange point. That's like tossing a cone on a table and trying to make it end up standing on its nose. Or make the nose...

I am trying to solve the equation like this, from sympy.solvers import solve from sympy import Symbol import math x = Symbol('x') A, B, C, D = 0.59912051, 0.64030348, 263.33721367, 387.92069617 print(solve((A * x) + (B * math.sqrt(x**3)) - (C * math.exp(-x / 50)) - D, x , numerical = True))...

Hi everyone, I'm pretty new to electromagnetism and have no experiences in this topic. I have a signal generator (Digital Dual Channel Funktion Signal Generator) and want to generate two signals (530 and 550 Khz signal) and want to transmit these generated signals to the points on a table...

We know from first law of thermodynamics for a closed system that ##dE##=##\delta Q## -##\delta W## , my question is that for a closed adiabatic system net heat transfer =0 this mean net change in energy = work done , does that mean for an adiabatic system work done is a point function as...

If I understand correctly (dubious), given a consistent theory C (collection of sentences), Kripke proposes to add a predicate T so that, if K = the collection of all sentences T("S") for every sentence S in C, ("." being some appropriate coding) then the closure of K∪C forms a new theory C*...

The energy-momentum tensor of a free particle with mass ##m## moving along its worldline ##x^\mu (\tau )## is \begin{equation} T^{\mu\nu}(y^\sigma)=m\int d \tau \frac{\delta^{(4) }(y^\sigma-x^\sigma(\tau ))}{\sqrt{-g}}\frac{dx^\mu}{d\tau}\frac{dx^\nu}{d\tau}.\tag{2} \end{equation} The covariant...

Elementary particle can be consider as a "wave packet" of the field,but a "packet" of field must have a size.Why do we know elementary particle is point particle?

After looking around a bit, I found that, considering the polar axis to be along the direction of the point charge as suggested by the exercise, the following Legendre polynomial expansion is true: $$\begin{equation}\frac{1}{|\mathbf{r} - \mathbf{r'}|} = \sum_{n=0}^\infty...

This probably occurs with salt too but let's concentrate on xylitol: you heat water till it boils, put the hot water in a cup and add a tsp of xylitol. It boils again violently for a couple of seconds. The high school explanation is that the boiling point of the water is lowered. I'd like to...

Not quite sure how to approach this question - do I need to calculate -qEd for all three charges and then the electron and add them together? Thanks

So I let x be the distance from P. I then considered moments about R and got this: 1) (40g)(x-3) = 40gx - 120g and this is anticlockwise 2) (30g)(0.5) = 15g and this is anticlockwise 3) (2.5g)(2) = 5g and this is clockwise And then by equating clockwise and anticlockwise I get this: 40gx -...

This is the form of the function above: I started by equating (1) to 1/2: $$T(\varphi)=\frac{r^{2}+\tau^{2}-2\tau\cos\varphi}{1+\tau^{2}r^{2}-2\tau r\cos\varphi} = \frac{1}{2},$$ which can be rearranged to: $$2r^{2}+2\tau^{2}-1-\tau^{2}r^{2}=2\tau\left[2-r\right]\cos\varphi$$ using...

I understand how they arrived at the answer of 2Q , but i have a couple of questions on this. If one of the charges were negative for example how would the resultant potential be found then? at the middle point would i add the positive charges and subtracted the negative ? Also what would the...

The problem of the interaction of a point charge with a dielectric plate of finite thickness implies the existence of an infinite series of image charges (see http://www.lorentzcenter.nl/lc/web/2011/466/problems/2/Sometani00.pdf). I introduce notations identical to those used in this work. The...

In Tipler & Mosca 5th edition p173 it defines neutral equilibrium as a point in a U-x curve where ##\frac{dU}{dx}=0## and also ##\frac{dU}{dx}=0## for a small displacement either side of the point. However I do not understand why ##\frac{dU}{dx}## remains ##0## either side of the inflexion...

I got the answer: E(P)=(k*Q)/(3î )−(k*Q*ĵ) /2 Can someone confirm if this is the right answer?

hi, all great brains, I have a question about BVP, which confused me a while, maybe someone can help to clarify it. For a point source with Dirichlet boundary in a 2D domain, the response at any coordinate except the source point is dependent on the surface of the source, for example, heat...

Summary: Potential at origin of an infinite set of point charges with charge (4^n)q and distance (3^n)a along x-axis where n starts at 1. From V=q/r, we find Vtotal=sum from 1 to infinity of (4/3)^n(q/a), which diverges. There cannot be infinite potential because there is a finite electric...

This is my attempt at a solution. Point A is the center of the circle (6,8) and Point B is the given point (12,16). I believe that the shortest path would be the one that is equal to the sum of CE and EB or its symmetrical complement. (I forgot to put a point where the top line intersects the...

These questions keep appearing in my past-papers and yet at no point in the course notes can I find a worked solution. Unfortunately I'm not sure where to start. My initial thoughts were regarding getting an equation using known values but w.r.t. to t and integrating for v, but like I said I...

I tried to use F/S = E.ε to find the new length after deformation and than use pytagoras theorem in right angled triangle to find how much did the middle point lower. But it was said to me that my method is wrong and that there exists some formula to solve it. Can you please tell me where could...

Hello! I'm trying to understand the concept of escape velocity, and I know you equate the initial mechanical energy to the final mechanical energy, where the final mechanical energy is at a distance of infinity. I know that the gravitational potential energy approaches 0 as the distance r gets...

I've been looking into how adding sodium chloride or calcium chloride to snow reduces the freezing point, and why this occurs. The really simple reason I found on this website: https://www.thoughtco.com/how-salt-melts-ice-3976057 , which simply stated that the salt ions get in the way of the...

I already got the answer for the case a but at the case b, i don't know how to sum all of the torques. I'm thinking of using integral, but i don't know where to put the pivot point for the torque. I don't know how to search for the pivot point. Can anybody give me hints so i could find the pivot...

Let ##V'## be the volume of dipole distribution and ##S'## be the boundary. The potential of a dipole distribution at a point ##P## is: ##\displaystyle\psi=-k \int_{V'} \dfrac{\vec{\nabla'}.\vec{M'}}{r}dV' +k \oint_{S'}\dfrac{\vec{M'}.\hat{n}}{r}dS'## If ##P\in V'## and ##P\in S'##, the...

A 2000 kg truck is resting at the top of a parking lot ramp which is at a 15 degree slope. It is then shifted into Neutral and starts moving. How long does it take the truck to get from A to B in seconds? There is a 15 degree slope on the ramp. uk is 0.08 Assume there is no air resistance.