Point Definition and 1000 Threads

In class, we did a lab to determine the boiling point of rubbing alcohol. We used a thiele tube filled with water and place a test tube attached to a thermometer w/rubber band in it. However, we never saw any signs of boiling. We conducted several trials, the temperature went all the way above...

Why is 1/3 considered a number line point when the decimal expansion never seems to stop at a point (if this is indeed the case)?

Homework Statement for M2 , if i take the moment at pont C , then my ans would be (0.3i) x ((125X(3/5) j +125(4/5) k )= 30j +22.5k Which is not same with the book which use moment about D . why ? Is the value at the triangle at te upper part incorrect (circle part) ? Homework EquationsThe...

Homework Statement I'm having problem of finding the point where the line of action intersect with CD , hot to do it ? Fx = -500cos60 - 250(4/5) Fy = 300 + 500sin60 + 250(3/5) FR = 991N Homework EquationsThe Attempt at a Solution

Homework Statement I managed to get Fy = 900N , Fx = 200N and FR= 922N , how to get the distance from A is 3.56m ? tetha= arc tan (922/200) = 77.5 degree Homework EquationsThe Attempt at a Solution

At the outset, I want to explain that this is a problem I came up with myself. It's not actually homework, and I suspect it is deeply conceptually flawed in some manner that I have yet to determine. 1. Two point charges of like polarity, ## q_1 = q_2 = 1C ##, start out separated by distance ##...

I have a solenoid, Length L, number of turns N, ampers I Radius R I have a Point P(x,y,z) anywhere around said solenoid. How can I calculate the field strength at point P, note it is OUTSIDE the solenoid, and could be anywhere outside. Assume the origin is the center of the solenoid, let's...

Homework Statement 1. Compute the electric field vector at the position of charge B for the case where q_{A}=4q_{C} and r_{1}=2r_{2} 2. Suppose that all three charge are positive and that q_{A}=4q_{C} . Consider the case where f q_{B} is moved to the right by a distance dr. Now r_{1} = 2r+dr...

Homework Statement the critical point is the point which the f'(c) = 0 or f'(c) = doesn't exist . How if I'm asked to find the stationary point . In this question , the critical point is x=0.071 , -14.071, 3 , and -2 So, if i am sked to find the stationary point , it should be only x=0.071 ...

I want to verify whether I am correct .As the title suggests It is about point where potential is zero (point other than infinity) Note:x is distance of neutral point from charges Firstly,I would like to ask Is coordinate system necessarily be there 1) If there are two positive charges for the...

A rod of length L and mass M is rotating with angular velocity w about its center of mass. What is its angular momentum with respect to a rotating point 1/4L from the rod's end? What about a stationary point? Homework Equations With the respect to the center of mass, angular momentum L = Iw =...

How to find potential ENERGY between two point charges?I know how to find potential difference between two points and I also know how to find potential at any point . potential difference between two points 1 and 2 is simply ##V1##-##V2## potential at any point r=V While source charge is Q...

I understand why an impure solid will have a decreased melting point, however, in my recent organic chemistry lab section I mixed two finely ground pure solids together and observed that the mixture melted at a lower temperature than either pure solid. I understand this in principle, but...

Homework Statement the ans given is 95Nm , but i gt 80.9Nm , which part i did wrongly ? Homework EquationsThe Attempt at a Solution 20(4) -39(5/surd 26(3)) +39(1/surd26)(1) -60(3/5)(1)+60(4/5)(3) =80.9[/B]

Homework Statement In this question , I'm asked to find the magnitude of P . Homework EquationsThe Attempt at a Solution Resultant moment about O = -10cos30 (4√3) -10sin 30 (10 +15sin30(2) + 15cos30(4√3) -10cos30(4√3) -10sin30(4) -15cos30(4√3) -15sin30(7) +10cos30(4√3) +10sin30(11) +P cos...

Find the point on the plane x − y + z = 8 that is closest to the point (1, 3, 6). This what I have so far Z = 8-x+y d = Sqrt ((x-1)2 + (y-3)2 + (z-6)2) f(x,y,z) = d2 = (x-1)2 + (y-3)2 + (z-6)2 Substitute for z = (x-1)2 + (y-3)2 + (2-x+y)2 Not sure how to move forward...

All elementary particles, which are not made up by any other particles (electrons, quarks), are said to be zero dimensional and have no size. But why not? Are electrons literally zero dimensional particles with no size?

In 'an introduction to quantum field theory' by peskin, he writes: To analyze the photon one-point function, note that the external photon must be attached to a QED vertex. Neglecting the external photon propagator, this amplitude is therefore: I really cannot justify this equation. Can...

Homework Statement i can't understand why when the total moment at B is positive , the object is not sliding ? can someone help to explain ? Homework EquationsThe Attempt at a Solution

Homework Statement :[/B] A projectile is given initial velocity 80 m/s ( V0 ) at angle 60° above the horizontal. Find the time it takes to reach to the highest point and find the maximum height. (g = -10 m/s2) Homework Equations :[/B] 1. y_{final} = y_{initial} + v_{y_{initial}}t + \frac...

Homework Statement Chain of mass M hangs between 2 walls with its ends at the same height. The chain makes an angle θ with each wall. Find the tension at the lowest point of the chain. a) By considering the forces on half of the chain. b) By using the fact that the height of the chain is...

What's the point of the elif statement? Why not just keep the if and else statements and leave it at that? Can't the if statement be replaced with just if? Thanks.

My first homework for electrostatics course I'm taking is to find the vector of electric field of a completely hollow sphere (radius r, surface charge density σ in a point A, by integrating the electric field through the whole sphere. I already figured out the electric field of a ring in a point...

Hi. I have problem simulating this circuit in Multisim: (LTSpice) Here is scheme from Multisim: When I run transient analysis, I got this: ------ Checking SPICE netlist for Design3 - Saturday, September 26, 2015, 10:58:03 AM ------ ======= SPICE Netlist check completed, 0 error(s), 0...

Homework Statement Why the moment isn't=15* 3Nm? Since we are taking moment about point O...it's 3m away from O Homework EquationsThe Attempt at a Solution

Homework Statement A ring of radius R lies in the x-y plane with the center at the coordinate origin. The ring is uniformly charged with with a uniform charge density +λ. a) Charge +q is brought along the z-axis from -∞ to the center of the ring. What is the increase in total potential energy...

Homework Statement A model for the suspension of a vehicle is shown where the spring has stiffness k = 178 N.mm and an unstretched length of 347 mm. Here is the picture: http://i.imgur.com/1dTVs12.jpg Part a asked to determine the value of P and the force supported by member AB so that the...

In the triangle ABC the point D lies on the side BC and point E on the side AB. BD = AC, AD = AE and AB ^ 2 = AC * BC. Show that \angle BAD = \angle CEA

Homework Statement A 100 lb vertical force is applied to the end of a lever, which is attached to a shaft at O. Determine (a) the moment of the 100 lb force about O (b) the horizontal force applied at a that creates the same moment about O. Homework EquationsThe Attempt at a Solution I know...

Hello, I was working on a classical mechanics problem, and I suddenly came up with this question: Let's think about a point in a 2-D plane. This point is represented by (r, θ), where r is the distance between the origin and the point and θ is the angle measured from the x-axis. Now, what is...

Let (X, d) be a complete metric space, and suppose T : X → X is a function such that T^2 is a contraction. [By T^2, we mean the function T^2 : X → X given by T^2(x) = T(T(x))]. Show that T has a unique fixed point in X. So I have an answer, but I am not sure whether it is correct. It goes as...

Find the curvature at the point (2, 4, −1). x = 2t, y = 4t3/2, z = −t2

Hi What would be the mathematical approach for calculating the resistance between two close points on an infinite plane of resistive material? And if the plane was circular/square/rectangular with the two points at the cente?

Homework Statement A point charge q is at the center of an uncharged spherical conducting shell, of inner radius a and outer radius b. How much work would it take to move the point charge out to infinity (through a tiny hole drilled in the shell)? [answer: q2/8πε0)(1/a - 1/b) Homework...

Homework Statement So I have to prove that the total velocity of a particle on a wheel is Vcm+Ui=Vi where Ui is the particles velocity if the wheel's center of mass wasn't moving so just v=omega*R I'm assuming and Vcm is the velocity of the center of mass and Vi is the total velocity of the...

The Wikipedia page on the heat of vaporization has a nice graph showing the heat of vaporization going to zero at the critical points of various substances. Is there a known form for the heat of vaporization as a function of temperature near the critical point? I imagine it is probably a power...

Homework Statement Determine from the left graph the speed at t1. Answer: Draw the tangent (right graph) at t1 and determine the slope. v = 1.4/0.30 = 4.7 m/s 2. The attempt at a solution The slope is (Y2-Y1)/(X2-X1). t1 coordinates are (0.24-0.25, 0). In order to get the answer I should...

Hello everyone. Hopefully someone would be able to help me with this problem. The question states: Two point charges qa = -12 micro coulombs and qb = 45.0 micro coulombs and a third particle with unknown charge qc are located on the x axis. The particle qa is at the origin placed so that each...

İn some articles, I see something... For example, Let we define a sequence by ${x}_{n}=f{x}_{n}={f}^{n}{x}_{0}$$\left\{{x}_{n}\right\}$. To show that $\left\{{x}_{n}\right\}$ is Cauchy sequence, we suppose that $\left\{{x}_{n}\right\}$ is not a Cauchy sequence...For this reason, there exists a...

The question posed: "An object is located to the right of a mirror that in concave in its [the object's] direction. If the object sits on the focal point of the mirror, what answer best describes the image formed?" Our class is united in the notion that as the rays would be parallel...

Homework Statement Two charges q1=+9c and q2+-1c are separated by 2m. Where is their neutral point? Homework Equations E = E(+) + E(-) E= k q/r^2 The Attempt at a Solution k q1/(2+x)^2 = -(k q2/x^2) When I solve for this equation I end up square rooting a negative number which would then...

Homework Statement An infinite line of charge with linear density λ1 = 6.9μ C/m is positioned along the axis of a thick insulating shell of inner radius a = 2.6 cm and outer radius b = 4.8 cm. The insulating shell is uniformly charged with a volume density of ρ = -656μ C/m3 1)What is λ2, the...

Homework Statement Four equal point charges q = +22.4 μC sit at each corner of a square. What charge Q, in μC, must be placed in the center so all the charges are in equilibrium? Your answer must include the sign of the charge. Homework Equations F = q1*q2 * k / r^2 3. The Attempt at a...

Homework Statement Find the electric field (both magnitude and direction) at point P located between the charges q1 = -3C and q2 = +4C. Point P is 1/3 of the charges' separation distance from q1 and 2/3 of the charges' separation distance from q2. Homework Equations E = kq/d^2 Etotal = E1 + E2...

When an neutrino is observed, it becomes a point particle, but it has mass. Is that mass not concentrated into a point? Why doesn't it collapse down to a micro black hole? What's the difference between a neutrino and a micro black hole of the same mass? I know it has 1/2 spin and other...

I want a better visual model of what Newton's gravitational force formula represents: (G⋅m1⋅m2)/d2 But there are two contradictory things that I'm having trouble reconciling: Multiplying the two masses shows a relationship between the two point sources, but using the area of the sphere to...

When Mac application icons are bouncing in the dock, does their velocity = 0 at their highest point? Here's what it looks like when you open a new application for Mac if you're not familiar. Another way I'm thinking about it: What if you have a strip of LED lights and its on a chase pattern...

Homework Statement I'm given an equilateral triangle of side length b with charges q at each corner and I have to find the y coordinate for point P on the y-axis where the electric field is equal to zero (E=0 other than the center of the triangle) 2. The attempt at a solution I figured I'd...

Homework Statement It's a question I ask to myself. A support turns at ##w_0## and can accelerate. A disk on the support can turn around itself (side view) but at start ##w_1=0##. I done the experimentation with 2 wheels but I'm not sure about my tests. There is an angle between 2 axes: The...

Homework Statement A uniform cylinder of mass M and radius R can be rotated about a perpendicular axle through its centre. A particle of mass m is attached to the cylinder's rim. The system is rotated with angular velocity w about the axle, which is held in a fixed direction during the motion...