Point Definition and 1000 Threads

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...

Hello, I am trying to estimate transfer function of unknown LTI system, given output and assumed input as point process. I have measurement of output, while input, which is assumed to be point process, could be created synthetically using known times and amplitudes. My questions: 1. What is...

Determine if the given point lies on the graph of the equation. (a - 1, a + 1); y = x + 2 Let x = a - 1 Let y = a + 1 y = x + 2 a + 1 = a - 1 + 2 a + 1 = a + 1 Yes, the given point lies on the graph of y = x + 2. Correct?

Determine if the given point lies on the graph of the equation. (a, 4a); y = 4x Solution: Let y = 4a Let x = a y = 4x 4a = 4a Yes, the point (a, 4a) lies on the graph of y = 4x. Correct?

The action for a relativistic point particle is proportional to the infinitesimal invariant length ds. Is there some more intuitive explanation for this? The action is defined by taking the time intergal over the difference between the kinetic energy and the potential energy. So how does this...

I know Earth's north pole points to Polaris and during the 26,000-year precession cycle, it will also point to Demeb, Vega, and Alpha Draconis. But... Is there a reference that'll help me figure out what Proxima Centauri b's most likely pole star candidates would be? I know, so many variables...

I never got an answer to my original question Why can't an event where light from that event hasn't reached our present point in space and time, reach a past point in space and time in 4D space...

Homework Statement Let A = (1,2,5) and B = (0,1,0). Determine a point P of the line AB such that ||\vec{PB}|| = 3||\vec{PA}||. Homework EquationsThe Attempt at a Solution Initially, writing the line in parametric form\vec{AB} = B - A = (0-1,1-2,0-5) = (-1,-1,-5)\\ \\ \Rightarrow \vec{v} =...

Homework Statement So I want to know the distance to 2. The proton is at v=0 at the 1. We know that: q=1.602*10^-19 point 1 L=1mm v=1.1*10^6 at point 2 F=1.44*10^-12 at point 1 Homework Equations [/B] E=(1/4πε)*(q/r2) ΔV=∫E*dr=(1/4πε)*q∫(1/r2)=(1/4πε)*q*(1/r2-1/r1) ΔU=ΔK=mv2/2...

Reference point was chosen to be at Va. I'm trying to understand the logic behind it. It is clear that Vc = - Vs because if Vc was the reference point at Va the voltage potential between Va and the reference point Vc is Vs. Therefore, Va = Vs, Va - Vc = Vs if Vc is reference. However, when Vc...

I'm currently trying to solve the following two-point boundary problem by means of the shooting method: To clarify, I'm investigating the optimal route of aerial/marine vehicles from one point to another point, considering a flow field. * The starting and ending locations are set as x0, y0...

Hello Today we did a lab and one of the activities was having a compass underneath a wire while the current was off. The wire was straight so that it was directly aligned to be with the needle of the compass. One the current was flowing, the compass arranged itself in that it was not exactly 90...

When solute particles are added to a solvent boiling point increases, I am quite clear with its explanation (in terms of vapour pressure) but when it comes to freezing point, why does it decrease? What does it have to do with vapour pressure? My textbook says it's because liquid and solid state...

Some things I did not get are, 1): In the third para, it is said that potential approaches ##\infty## at ##Q##, why ? 2): In last para, The z component of field by ##Q## is said to be ##-Qh/(r^2 + h^2)^{3/2}##, Why ? should not it be ##+Q## not ##-Q## has the charge itself is positive. 3): I...

I know that when anything starts moving close to the speed of C (light speed) it ganes mass from an outside perspective. Does the same apply in the reverse? From the perspective of the thing that moving close to C does everything around it lose mass??

Hi. I have this problem in trying to solve this PDE analytically. The PDE is represented by this diagram: Basically this is solving the Laplace equation with those insulated boundaries except it has that point diffusing its value across the plane. I know how to solve the Laplace equation...

Homework Statement [/B] Hello, I trying to solve for the minimum value that the x and y components reach in plot (A). I know that you can perform this using IgorPro but I would like to know how to solve for it using Excel. The plot was constructed using the following data points: 110...

Hi guys, I am just wondering if it is possible to calculate/estimate the location of measurement point on a rigid body? For example, let's say we have a rigid body that is in motion. We attach a sensor, say an accelerometer on the surface of the rigid body. Now can we estimate the location of...

I'm just reading over some experimental notes for neutron activation analysis and I see the mention of a spacer being placed between the irradiated sample and the detector face. What does a spacer actually do? I did a quick google but couldn't really find anything.

Homework Statement http://i.imgur.com/In40pGm.png Answer: C Homework Equations f'(x)=slope=(y1-y2)/(x1-x2) The Attempt at a Solution I can't even list a valid formula for that... like I tried to integrate f'(x), but f(x) is with y so I don't think I am thinking in the right direction. What...

Hi all. Brushing up on some of my force and torque stuff so I can do some modelling in software. Homework Statement I have a system as shown in the picture. A force F acts at point A, which is the end point of the lever AB. Connected to the lever is a link BC, and connected to BC at point C is...

there is power source grounded, with electric power of 20v the negative side of the wire we connect to a pointy metalic button and the positive side of the wire we connect to a metalic conductive ring with radius of 7.5 cm as...

Homework Statement Consider ##\mathbb{R}^\omega## in the uniform topology. Show that ##x## and ##y## lie in the same component if and only if ##x-y = (x_1-y_1,x_2-y_2,...)## is a bounded sequence. Homework Equations The uniform topology is induced by the metric ##p(x,y) := \sup_{i \in...

The moment of inertia of a rod with consistent density rotating about its end is M(L^2)/3. However, if you treat the rod as a point mass and try to calculate this using mr^2, you get M(L/2)^2=M(L^2)/4. Why doesn't this work?

So currently I'm stuck in a topic which I don't understand because either my teacher is doing wrong or I'm just blind to see my mistake I want to know the velocity of a object at the highest point in a swing (looping is the German word, I'm not sure if it's the same in English) (I don't know...

I am designing a dust collection system for a powder mixing project. My current setup is basically a tent (roughly 6ft X 4ft X 7ft) with a dust collector tube hanging from the ceiling (or coming from the floor). I know the CFM, air properties, and pipe area at the end of the dust collector...

Homework Statement Three equal point masses, mass M, are located at (a,0,0), (0, a, 2a) and (0, 2a, a). Find the centre of mass for this system. Use symmetry to determine the principle axes of the system and hence find the inertia tensor through the centre of mass. (based on Hand and Finch...

If a smooth sphere with radius a is fixed on a plane, and a particle is projected horizontally at the highest point outside/on of the sphere with speed (4ag/5)^0.5, I know that the particle will lose contact with the sphere when it makes an angle of theta with the upward vertical, where theta is...

Homework Statement 6g of non-volatile solute dissolved in 500g of water freezes at 272.64K. What is the molar mass of the solute? Data given- Tsolution = 272.64K Kf = 1.8 wsolute = 6g wsolvent = 500g 2. Homework Equations ∆Tf = T0 -Tsolution ∆Tf = Kf × molality (m) The Attempt at a Solution...

∴1. Homework Statement Find an equation for the plane that contains the point (1,-1,2) and the line x=t, y=t+1, z=-3+2t? 2. Homework Equations The Attempt at a Solution I don't know what I am doing wrong but everytime I try to do these plane questions my amswer is always the opposite sign of...

refer only to the image above, not the question 4.) Two point charges, Q1 and Q2, are placed 0.30 m apart on the x–axis (shown in the figure above) Charge Q1 has a value of –2.50 x 10–6C. The net electric field at point P is zero. a. What is the sign of charge Q2? ____ Positive ____...

Hello! So this is going into physics because it is a physics problem, but it is maths that is the real problem. So if you came here to help someone with physics and not maths I'm sorry. 1. Homework Statement Find the force of repulsion between two point charges of +1C and +3C if they are...

Hello all. i am after some help and hopefully you are the right people for this! i have a problem will a kitchen wall cabinet. i can only get fixings which rate at 40kg, but i work out my cabinet fully loaded (including self weight) could be 95kg. i have attached a drawing which hopefully...

Homework Statement 2. Homework Equations are given in the above picture 3. The attempt at the solution In part a) I simply rearranged the other expressions given and subbed them into the relationship for relative velocity and came out with Vns= Qdot/ρsT(1- ρn/ρs).Then in part b) I started by...

Hi, I am trying to draw circles at the end points of a line but circle centre is not exactly on the end point of the line. Can somebody please guide me. import java.applet.Applet; import java.awt.*; import javax.swing.*; public class JCircle extends Applet{ int x1=30; int y1=30...

Homework Statement Find the point "c" that satisfies the Mean Value Theorem For Derivatives for the function ## f(x) = \frac {x-1} {x+1}## on the interval [4,5]. Answer - c = 4.48 Homework Equations ##x = \frac {-b \pm \sqrt{b^2 -4ac}} {2a}## ##f'(c) = \frac { f(b) - f(a)} {b-a}## The Attempt...

Homework Statement I am trying to derive an expression for the potential of a positive point charge by bringing in another positive test charge in from infinity to a point at a distance R from the point charge. Homework Equations $$V_f - V_i = - \int \vec E \cdot d \vec r \, dr$$ The Attempt...

1. Homework Statement a point mass is projected at an angle of 60° from the horizontal. it collides with the sphere at a maximum height of trajectory with a sphere of radius of 72.5cm such that it is projected off the sphere once again at an angle of 60° from the horizontal.The sphere, due to...

Homework Statement Only Number 1, not number 2 Homework Equations Dew Point Temperature T = Saturated Temperated at Vapor Pressure Partial Pressure = (mole fraction) x (Mixture Pressure) The Attempt at a Solution The dew point temperature is only dependent on the pressure of the water...

Homework Statement Only Number 1, not number 2 Homework Equations Dew Point Temperature T = Saturated Temperated at Vapor Pressure Partial Pressure = (mole fraction) x (Mixture Pressure) The Attempt at a Solution The dew point temperature is only dependent on the pressure of the water...

I came upon this: http://physics.stackexchange.com/questions/174514/will-the-electrostatic-force-between-two-charges-change-if-we-place-a-metal-plat/323006#323006 question on Physics Stackexchange which I found very interesting. The configuration is basically two positive point charges q and...

Homework Statement A heavy mass m is attached to thin wire and whirled in a vertical circle. Then the wire is most likely to break A only when mass is at the lowest B somewhere between lowest point and horizontal point C only when mass is horizontal D only when mass is at highest point...

Homework Statement A long, straight wire lies along the z−axis and carries a 4.20 −A current in the +z−direction. Find the magnetic field (magnitude and direction) produced at the following points by a 0.400 −mm segment of the wire centered at the origin. Homework Equations ## \vec B ## = 2...

Can someone explain, what means that we can choose any arbitrary point to calculate moment and result will always be identical? If I choose point 1 ...20kg x 1m = 20kg x 3m...seesaw right side will fall down If I choose point 2...20kg x 2m = 20kg x 2m...seesaw stay horizontal So this two...

Homework Statement : STATEMENT:[/B]A point charge at rest is released in an electric field. It will move along the electric field line...(1) REASON: The force on a point charge is along the field line...(2) State whether: A) 2 is the correct reason for(1) B) Both (1) and (2) are correct but 2 is...

Hello all, These days I am studying rotation and rolling of bodies. We know a body can be made to rotate about any point. Let's assume that an external force is acting on the rotating body fixed about the point of rotation, and this force made the body rotates faster that is its torque produces...