Point Definition and 1000 Threads

Homework Statement I've seen many books writing the cosine rule like this: a^2 = b^2 + c^2 - 2bc cos A My electricity textbook for an electric field in a point between two charges says this: E resultant = root[E1^2 + E2^2 + 2*E1*E2*cos(angle between E1 and E2)] In the first equation it is -2...

Homework Statement Find the potential at points P1, P2, P3, and P4 in the diagram due to the two given charges. Homework Equations VP =k∑qi/ri p = q ⋅ d The Attempt at a Solution I'm not sure how to approach the problem. I thought about using that given equation four times and adding it all...

I was just thinking of basic definitions of geometry and i came to this question, so how could i prove that only one straight line passes through two distinct points.

There is a clear problem with the continuing belief that (any) point particles exist in nature. Quantum mechanics, relativity and even classical physics all forbids this approach. Let's explore why: 1). Quantum theory forbids point particles, because points themselves do not make sense in phase...

Homework Statement I am not sure how to get Nd in this question ( circled part) I am not sure the exact location of the point where the author want to find the pore pressure . Can someone help ? This notes is confusing Homework EquationsThe Attempt at a Solution I think the Nd can be only...

Hi all, My first physics question here - hope it's worthy and someone has some experience here :) Hypothetically speaking, say you have an engine capable of swallowing 85lb/min of air at an absolute pressure of ~280kpa at sea level running a turbocharger running the compressor which the...

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 Sorry, English is not my first language. Is Turkey Point nuclear powerplant in Florida safe for the storm surge of Irma ?

After solving a homework problem, I realized I don't know what to do when there's a dipole and a point charge but the distance from the charges in the dipole is greater than the distance from the center of the dipole to the charge. As my homework problem stated, with a little context added...

Object A starts from the origin velocity 3 m/s and object B starts from the same place with the velocity 5 m/s, 6 seconds later. When will B Catch up with A?

For 3 (a), I feel like I've gotten it down correctly, but comments would be appreciated! 3 (b), I'm not too sure about; could anyone please give a thorough review and point out mistakes if there are any? Number 4, I have no idea where to even begin. I've spent nearly an hour brainstorming, but...

Homework Statement Two positive charges q1 = q2 = 2.0 μC are located at x = 0, y = 0.30 m and x = 0, y = -0.30 m, respectively. Third point charge Q = 4.0 μC is located at x = 0.40 m, y = 0. What is the net force ((a)magnitude and (b)direction) on charge q1 exerted by the other two charges...

1. The problem statement, aall variables, and given/known data I need to find the angle between a point on the ellipse and the ellipse's center shown in the figure below: The known variables are 'd', the distance between point O (the center of the ellipse) and point A, and 'a', the angle...

Homework Statement "Let there be two point charges ##q_1=3.5μC## and ##q_2=-3.5μC## located at ##(0,0.3 m)## and ##(0,-0.3 m)## respectively. What force do these two charges exert on a test charge ##Q=4.5μC## at ##(0.4 m,0)##?" *title should read "due to two point charges"* <Moderator's note...

Hi all, I was trying the understand theory behind Fourier and Laplace Transform (especially in the context of control theory) by reading the book "Complex Variables and the Laplace Transform for Engineers" written by "Wilbur R. LePage". In section 6-10 of the book the author touches on the...

Homework Statement What is the equation of a straight line passing through (1,2) and normal to ##~x^2=4y## Homework Equations Slopes of perpendicular lines: $$m_2=-\frac{1}{m_1}$$ The Attempt at a Solution $$x^2=4y~\rightarrow~m_1=y'=\frac{x}{2}$$ $$m_2=-\frac{2}{x}$$...

Homework Statement Dear All, I'm having a hard time solving the following problem: A point of mass is moving on a circular plane (Oxy), where the circle's formula is: The force acting on mass "m" is defined as: We're looking for velocity of point "m" in position (1,1) =V1, and in position...

Things I have thought of till now: Acetonitrile with HI additive Acetonitrile with DMSO additive The problem with the first would be that HI is in an around 55% aqueous solution and water doesn't play well with the perovskite. Meanwhile, the second might end up needing enough DMSO to...

$\tiny{231.12.3.63}$ $\textsf{Determine the smallest distance between point $P(1,1,1)$}$ $\textsf{ and the line $L$ through the origin}$ $\textsf{ $L$ has the direction $\langle -4,-5,8 \rangle$}$ $\textit{ok I know the formula to use basically is}$ \begin{align*}\displaystyle...

The question: The line L1 has equation $$r = \left( \begin{array}{ccc}4 \\-1 \\0\\\end{array} \right) + t\left( \begin{array}{ccc}1 \\1 \\-1\\\end{array} \right) $$, and point A has coordinates (4, 8, -3). Find the coordinates of point B on L1, such that $$\overrightarrow{AB}$$ is...

Homework Statement Considering the figure. The liquid has a density $$\rho$$. What is the pressure at B? http://imgur.com/HHMiWcU (I put the link because the image uploaded doesn't work) The Attempt at a Solution In a solution that I have found on internet, it is said that the pressure in B is...

$\tiny{231.12.3.65}$ $\textsf{Determine the smallest distance between point $P(1,1,1)$ and the line $L$ through the origin $L$ has the direction $\langle -4,-5,8 \rangle$}$ $\textit{ok I'm not real sure I understand this question so assume}\\$ $\textit{the line equation is derived first going...

Homework Statement A projectile, launched at A with an initial velovity of 24m/s at the angle θ, impacts the vertical wall at B. Compute the angle θ that will maximize the height of h of the impact point. What is this maximum height? Homework EquationsThe Attempt at a Solution I guess I have...

Homework Statement Find the magnetic field at the point distance R outside a rectangular loop of sides 2R, 4R carrying current I as shown in the attached diagram Homework Equations Biot-Savart Law The Attempt at a Solution Could I just break this up into 4 separate lines and then calculate...

Homework Statement Homework EquationsThe Attempt at a Solution Let's consider the primitive model of atom i.e. the nucleus is surrounded by an electron cloud. Let's say that the nucleus has charge qa and it moves a distance d from the center in the equilibrium position. ## E = \frac {kq}...

Homework Statement Homework EquationsThe Attempt at a Solution why not B?

Homework Statement find the shortest distance from (0,0) to the line passing A(2,3) and B(3,5) Homework Equations ## \frac{y-y1}{y2-y1} = \frac{x-x1}{x2-x1} ## y-y1 = m (x-x1) m1 * m2 = -1 (m1 perpendicular to m2) The Attempt at a Solution line passing A and B points ## \frac{y-3}{5-3} ## =...

Homework Statement A centrifugal pump has the following pressure – capacity characteristics: It is planned to use this for a process having the following system characteristic: (a) Determine the operating point for this pump with this system. (b) The actual flowrate required by the...

Homework Statement In an infinite flat layer of thickness 2d, volume charge density is given according to the law: ρ=(ρ°)(x)/d and (-d≤x≤d). Here, x is the axis perpendicular to the plane. In the layer, there is a thin channel in which a point dipole of mass m and dipole moment p is placed...

Homework Statement Consider the arrangment of charges (fixed in place) shown in the figure. The square has side length d. (Figure 1) Now suppose the particle with charge q is released. It is "kicked" so that it's initial speed is v. After an unspecified trajectory, it is observed that the...

Hey! :o I want to rotate the point $(10, 11)$ with rotation angle $\frac{\pi}{3}$ around the point $P=(-1,-1)$. I have done the following: We translate about $-\vec{OP}$: \begin{equation*}P'=(-1\mid -1)-(-1\mid -1)=(0\mid 0)\end{equation*} We rotate around the origin...

I have posted this in University linear algebra, but it is possible there is a simple answer for this and the the problem belongs in some other forum. I apologize if that is the case. I am starting with 3 points in 3 space, along with the centroid of the full data set. The data is in principle...

Hello all, I need your assistance with the following: Find the equation of the line that goes through the origin (0,0) if it is known that the sum of distances of the line from A(2,1) and B(1,4) is equal to \[\sqrt{8}\], and it is also known that the line is between the points. The formula I...

Homework Statement Two spherical point charges each carrying a charge of 40 mC are attached to the two ends of a spring of length 20 cm. If its spring constant is 120 Nm-1, what is the length of the spring when the charges are in equilibrium? Homework Equations 1) F = k*(q^2)/r^2 where k is...

Hello! I am reading Peskin's book on QFT and I reached a part (in chapter 4) where he is analyzing the two-point correlation function for ##\phi^4## theory. At a point he wants to find the evolution in time of ##\phi##, under this Hamiltonian (which is basically the Klein-Gordon - ##H_0## - one...

a cruiser is 12 km due west of a destroyer . the cruiser is traveling in a direction 60 degrees N of E at 30 km hr^-1 and the destroyer is traveling at 15 km hr^-1. find the direction the destroyer must travel in order to get as close as possible to the cruiser there is complicating way to do...

Homework Statement In two dimensions, the moment of a force can be calculated using the scalar method, MO=Fd, where F is the magnitude of the force and d is the perpendicular distance from the line of force to the point where the moment is being considered. Using the scalar method, calculate...

Homework Statement Three point charges each carrying a charge of 11.0 µC are located at the corners of an equilateral triangle of side 15.0 cm. Calculate the magnitude and direction of the force on each charge. Homework Equations k = 9.0x109NM2C-2 F = k⋅(Q1⋅Q2)/r2 The Attempt at a Solution...

hi i am trying to figure out the way to calculate the freezing point of an aqueous solution which have 5 different components. if someone can refer me to an example or give me and example it will be great thanks in advance sharon

Homework Statement Find the distance between Helsinki and Seattle along the shortest route. Where is the northermost point of the route, and what is its distance from the North Pole? The longitude of Helsinki is 25ºE and latitude 60º; the longitude of Seattle is 122ºW and latitude 48º. Assume...

I'm attempting to use an algorithm translated from Jean Meeus: Astronomical Algorithms. The algorithm in question finds a geocentric position of the moon given a certain day. I have been able to find the geocentric longitude of the moon, but I don't know what this longitude is in reference to...

Suppose a charge q is placed at point x=0, y=0. A second charge q is placed at point x=8.0m, y=0. What charge must be placed at the point x=4.0m, y=0 in order that the field at the point x=4.0m, y=3.0m be zero?

Hi! According to the book "Renewable Energy on Power Systems" by Freris & Infield, the voltage rise due to injection of power in pcc can be estimated from the Thevenin equivalent representing the network "upstream" pcc (Figure 1). The Thevenin voltage can be taken as the nominal voltage in the...

Hey, Not sure if this is the correct sub-forum to post this question. I'm still kinda new here, so sorry if I got it wrong :smile: I have a laser module with a fixed focal point of 16 mm and I'm trying to collimate that light into a beam. The point of focused light is at most a quarter...

Hi Guys, I've been learning electric field, and i want to ask about this question.EF net = EF1 + EF2 my EF1 = 9 x 109 * 4 x 10-8 / (0.6)2 = 1 x 103 (From Q1) EF2 = 9 x 109 * 2 x 10-8 / (0.3)2 = 2 x 103 (From Q2) then EFnet = (2+1) x 103 = 3 x 103 and what i get from key answer is 2.2 x 103...

Homework Statement Picture of the problem: I first need to calculate the magnetic field in point P caused by the piece of wire at z = R (so the top wire parallel to the y-axis). Homework Equations [/B] Biot-Savart law for magnetic fields: ##\vec {dB} = \frac {μ0*I} {4*π} * \frac {\vec {dl}...

it is possible to have two different tangents at the same point of a function?

Hello, I have this simple problem: f(x) and g(x) are both differentiable. f is monotonically increasing for every x. g has a local min at x=0. we define h to be h(x)=f(g(x)). Can we say anything about x=0 for h(x) ? I used the chain rule to find that h'(x) = f'(g(x))*g'(x). at x=0 g'(x)=0...

Find point P on the curve y = sqrt{x} such that the slope of the line passing through P and (1, 1) is 1/4. Tell me, must I use m = (y2 - y1)/(x2 - x1), where m is 1/4? Seeking point P means we need the coordinates of P or (x, y), right?

Would people assume my take on converting frequency to temperatures of specific frequencies would possibly cause a corelation between the two using a research table of precise temperatures which are matched to a focal point of a laser, of an object, at its resonance level and at room temperature...