Point Definition and 1000 Threads

Homework Statement find equation of plane P that is perpendicular to line L which passes through the point (-2,-2,3) Homework Equations ... The Attempt at a Solution [/B]line L passes through the points (1,2,1) and (0,0,-3) I have worked out the parametric equations of line L to be x=1-t...

http://www.nytimes.com/2017/01/06/nyregion/indian-point-nuclear-power-plant-shutdown.html This is very big news for a power engineer like me. I thought I would share it on PF and explain what the engineering implications are. Indian Point's nameplate rating is 2083 MWe Power supply for the...

Hello. Suppose you dissolve something in water. I know that the boiling point should increase because as the water boils the solute's entropy decreases, and the net entropy should increase. Now suppose, that I dissolve GI chlorides in the water. Each solution of the salt has the concentration...

I noticed that my windshield washer fluid has methanol in it to reduce the temperature of which it freezes. I know it freezes at approximately -28°C which gives us a concentration of MeOH at approximately ~30% by weight. However, when I try to calculate the required methanol using the mSolute...

Let f be a continuous function of a metric space, M, to itself with a dense orbit and a fixed point. I.e. there exists z such that the set {f(n)(z)} for all n ∊ N (where f(n) is the nth iterate of f) is dense in M, and there exists p such that f(p) = p. Does this imply that f spreads? I.e. does...

Homework Statement Let f(x, y) = x^2 + kxy + y^2 , where k is some constant in R. i. Show that f has a stationary point at (0, 0) for every k ∈ R Homework Equations ... The Attempt at a Solution I may have the solution or i may have gone completely wrong I am not entirely sure. i first found...

In order to compute the scattering probability that two particles of type 1 (associated to ##\phi_1(x)##) which come from the far past with the momenta ##p1## and## p2##, to scatter and evolve into two particles of type 2 (associated to ##\phi_2(x)##) with the momenta ##p3## and ##p4## , I am...

i know how to do the first two parts the x value of the max is 0 and of the minimum is 8 and 4 is the x value of the inflexion point. however i don't know how to do part 3

what are the stationary points of x-2xsinx in the interval of [0,3pi] i differentiated it and let it equal to 0 . i get when i let 1-2x cosx-2sinx equal 0 i can't solve it

Homework Statement What is the electric potential at P due to charges Q1 and Q2...

Hi guys and gals. Hobbyist, not a student. I've had great input here in the past. Thank you in advance for any direction and help figuring this out. -Seth- 1. Homework Statement I'd like to learn how to calculate relative humidity, saturation, and dew point under differing pressures and...

Homework Statement Determine the Work done by the electric field E = axX - ay2y in moving a unit positive charge from position p1 (-2,0,0) to position p2 (5,-1,3) the distances are in m Homework EquationsThe Attempt at a Solution I'm not really experienced with forums therefore my attempted...

Lab manual is confusing me, and I'm not sure if its actually wrong, or the wording is bad, or if this is because I'm not understanding something. It says: "Before a broth can be tested for nitrate reductase activity it must be examined for evidence of denitrification. This is simply a visual...

I want to make a 2D plot of points with different x, y coordinates and have colors depending on a separate variable. I have make column vectors for x and y coordinates and another column containing 1 or -1. I would like to represent the points with 1 as red and -1 as blue points. I have codes as...

Homework Statement Homework EquationsThe Attempt at a Solution The answer is F. I don't how to get this. I know that it is perpendicular and must have a horizontal tangent. How do I come to this answer?[/B]

Firstly I appologize, that I am not native english speaker and I don't study physics(but cybernetics we are getting just some general knowledge about physics), but hopeffuly I will write this right. Homework Statement We know that inside of a conductive object is protected from influence of...

Suppose that the Taylor series of a function ##f: (a,b) \subset \mathbb{R} \to \mathbb{R}## (with ##f \in C^{\infty}##), centered in a point ##x_0 \in (a,b)## converges to ##f(x)## ##\forall x \in (x_0-r, x_0+r)## with ##r >0##. That is $$f(x)=\sum_{n \geq 0} \frac{f^{(n)}(x_0)}{n!} (x-x_0)^n...

Homework Statement An object weighing 8.0 N is supported by two rope, which form the angles a and b to the horizontal, with tensions T1 and T2. angle a = 30 degrees angle b = 60 degrees I have calculated these values: T1 = 4N T2 = 6.93N How do I find the maximum tension of the obtained...

I'm having a little trouble starting on this problem. Can someone help? I was trying to solve it out, but I just ended up telling how to draw the center. Attached is the problem:

y = 3e^(−2x) −5e^(−4x) y'= −6e^(−2x)+20e^(−4x) How do I find the critical point at x? The answer is (1/2)ln(10/3) but I don't know how to get that answer Thank you

Homework Statement the point (log a, log b) exists on the unit circle. find the value of axb. round to the nearest thousandths. Homework Equations x2 + y2 = 1 The Attempt at a Solution x2+y2 = 1 loga2+logb2 =1 2loga+2logb = 1 2(loga+logb) = 1 loga + log b = 0.5 logb = 0.5−loga now i try...

Hi So the problem I have is I want to get the equation of motion of a vibrating beam under a nonlinear "Point" force. The equation would be like this for a distributed load (Which is not the case) But I want the load to be at a point at x=L So I have to options. Add an impulse dirac function...

Homework Statement Monochromatic light of wavelength 592 nm from a distant source passes through a slit that is 0.0290 mm wide. In the resulting diffraction pattern, the intensity at the center of the central maximum (θ = 0∘) is 3.00×10−5 W/m2 . What is the intensity at a point on the screen...

Homework Statement So I've calculated the person's corrective lens to need the power of -2.00D now I must find the new near point with the corrective lens on. The initial near point is 15cm and I converted the -2.00D into cm, which is -50cm (I hope). Homework Equations I've used this formula...

Homework Statement A closed loop carries a current of 8.0 A in the counterclockwise direction. The radius of the outer arc is 0.6m and that of the inner arc is 0.40m. What is the magnetic field at P? Homework Equations F = ILxB F = qV x B R = outer radius r = inner radius The Attempt at a...

Homework Statement There's a person on the ground in (0,0,0). An object comes from the sky and hits the ground at (a,b,0), but continues propagating, that is, it does not stop. I need to find the minimum distance between the person and the object. All we know is that the person is in (0,0,0)...

Assume we known that f(0) = 1 and f'(0)=2 Find xf^7(x)''(0) Will chain rule work here? is the u=xf^7 and y = u^7 I don't know if I am going in the right direction.

Homework Statement Write the parametric and cartesian equations of the line passing through ##P = (-\frac{3}{10}, 0, \frac{1}{10})## and parallel to $$r : \begin{cases} 10x + 4y - 3 = 0 \\ x + z = 0 \end{cases}$$ Homework EquationsThe Attempt at a Solution Since the two lines have to be...

Homework Statement In an experiment modeling point charges I had to find equipotential lines. I did so using a voltmeter. The results looked like this: Not a good quality picture, but the equipotential line on the right says 1.3 mV and the one on the left says 2.3mV. From this I had to...

Homework Statement Around a point charge there are three points: A, B and C. Determine the electric field vector for those points. Also, determine the force vector for q0 if it was in point B. Q = 10 µC, a = 1 m, b = sqrt(3) m, q0 = 10 pC 2. The attempt at a solution Here is the attempt at a...

[ Mod Note: moving this to Physics H/W ] Homework Statement for this question , I'm having problem with the shear stress at point E and shear stress at centorid. normally , the shear stress at the centoid will be maximum . But , in my working , I found that the shear stress at the centroid is...

Homework Statement In the example , I suspect the selected A (area) is wrong... From the notes , A' is the area of top (or bottom ) portion of the member cross sectional area . But , in the example , we could see that the selected area is located to the right of the point where shear stress is...

1. Homework Statement A fixed parallel plate capacitor is charged. A point charge is starting to move with an initial speed 1.0 m/s at shown initial position. The capacitance is 5.0 F. The mass of the point charge is 0.80 kg. Assume that the plate length is infinite. No gravity. The initial...

Homework Statement An object is thrown with speed 20 m/Sunder the angle pi/3 rad with the horisontal direction. In the highest point, the object is divised into two pieces with same weights. One of them, after the division has the speed 0. How far from the starting point do the pieces fall on...

Homework Statement In the beginning a point mass is rotating in a circle of radius L. The spring is providing the centripetal force (\vec{F}=-k\vec{r}) and the mass rotates with constant speed. At some point in time, a stick of radius a (a<<L)lands near the center of the circle in such a way...

Homework Statement If a wave y(x, t) = (6.0 mm) sin(kx + (600 rad/s)t + θ) travels along a string, how much time does any given point on the string take to move between displacements y=+2.0 mm and y=-2.0 mm? Homework Equations ω=2πf (but it's not necessary in this problem, this problem just...

A smooth vector field on the phase plane is known to have exactly three closed orbit. Two of the cycles, C1 and C2 lie inside the third cycle C3. However C1 does not lie inside C2, nor vice-versa. What is the configuration of the orbits? Show that there must be at least one fixed point bounded...

The limit below represents the slope of a curve y=​f(x) at the point​ (a,f(a)). Determine a​ f After finding the f(x) and a, I did this:8(3^2+3h(3)+3h(3)+h^2)-72 dividing by h getting h(8h^2+144) dividing by h; canceling the h's and the plugging in the limit h --> 0 getting 144. But I am...

Homework Statement While carrying contact lenses of D=-2.00 diopters, a nearsighted person takes a vision test and finds that his/her far point is 10.0m a) what is the person's far point without contact lenses? b) what lens power is required to correct the myopia fully? Homework Equations 1/f...

Homework Statement in photo 391 , we can see that the levelling work is back to the same point , which is TBM1 . so , the adjustment of correction is (Bs -Fs ) / number of points ... But in 392-394 , the levelling work is from a known point to a different point ... I'm wondering that is the...

Why does 3-methylbutyl ethanoate have a higher boiling point than 3-methylbutan-1-ol and ethanoic acid? Attempt at a solution: I know that the ester has a marginally greater molar mass but I wasn't sure if this is the only deciding factor, particularly considering the strength of the other...

Hello! (Wave) Let $v(x,y)$ be a harmonic function in $\mathbb{R}^2$. I want to compute $v(0,0)$ given that $v|_{x^2+y^2=1}=\sin{\phi}+1$, where $x= \cos{\phi}, y=\sin{\phi}, \phi \in [0,2 \pi)$. I I thought that we could use the following theorem. $(\star) \Delta u=0 \text{ in } B_R(0)...

Homework Statement Let ##F(x,y)=4sin(xy)+x^3+y^3## Use Newton's method to approximate the critical point that lies near ##(x,y)=(-1,-1)## Homework EquationsThe Attempt at a Solution I have a problem here because the derivative is not a square matrix. Hence, I can't find the inverse needed for...

Homework Statement The equation ## f(x,y) = f(a,b) ## defines a level curve through a point ## (a,b) ## where ## \nabla f(a,b) \neq \vec 0##. Use implicit differentiation and the chain rule to show that the slope of the line tangent to this curve at the point ##(a,b)## is ##-f_x(a,b)/f_y(a,b)##...

So, let's imagine we have a sphere of metal with a piezoelectric film all around the outside of it. If we applied a point force to one area of the sphere, how would the piezoelectric material react? Would it compress or expand at that point, and how can we measure the force based on the response...

Homework Statement Force F = 460 N acts perpendicular to the inclined plane Determine the moment produced by F about point A. Enter the x, y, and z components of the moment separated by commas. Homework EquationsThe Attempt at a Solution r(CA)=4j-3k u(CA)=4/5j-3/5k r(CB)=-3i+4j...

Homework Statement Given two planes, P1, P2. Find parametric equations for the line of intersection between the two planes. Homework Equations P1 = 2x -3y + 4z = 3 P2 = x + 4y - 2z = 7 The Attempt at a Solution Let N1 be the normal vector to P1, and N2 be the normal vector to P2. Then, N1...

Homework Statement ##W = x^2+5y^2## Show that ##\nabla W## is perpendicular to the level curves of W at ##(X_0, 0)## Homework Equations ##\nabla f(x,y) = <\frac {\partial f} {\partial x} , \frac {\partial f} {\partial y}>## The Attempt at a Solution I know that the gradient is always...

Why there is huge difference in M.P. and B.P. Of Oxygen (M.P. - 54K,B.P.- 90K) and sulphur (M.P. - 393 K, B.P. - 718 K)

Homework Statement Suppose that you have the following information concerning a differentiable function ##f##: ##f(2,3)=12##, ##\space## ##f(1.98,3)=12.1##, ##\space## ##f(2,3.01)=12.2## a) Give an approximate equation for the plane tangent to the graph of ##f## at ##(2,3,12)##. b) Use the...