Normal Definition and 1000 Threads

Ok so I remember doing these problems, but for whatever reason when I went to practice this one word problem for the final test I couldn't for the life of me remember how to do it. It's only been two weeks or so since I last worked at it. I remember the other problems fairly well and got this...

Let X be normally distributed with \mu =100cm and \sigma =5 cm (a) shade region P(X>105) https://www.physicsforums.com/attachments/1010 (b) Given that P(X<d)=P(X>105), find the value of d. wasn't sure if this meant that d is the left of 105 which would be larger in volume than X>105

Homework Statement Calculate the normal potential at 25 °C for the reaction: HA(aq) + e- → A-(aq) + 1/2H2(g) if the dissociation constant of HA is equal to 3.3*10-4 Homework Equations ΔG° = -RTlnK ⇔ -ΔG°/nF = RT/(nF)lnK ⇔ E° = RT/(nF)lnK The Attempt at a Solution Just...

I am trying learn how to graph Normal distribution with TI-Nspire CX CAS went to the Ti.com but just found a work sheet. or else I missed it some where. but saw some examples on the display. thanks ahead for help:cool:

Homework Statement The function f(x)=5x2+3e2x is invertible. Give the slope of the normal line to the graph of f-1 at x=3 Homework Equations (f-1)'(x)=1/f'(f-1(x)) The slope of the normal line × the slope of the tangent =-1 So basically I just need to find -f'(f-1(x)) at x=3 The Attempt at a...

Following on from my (still not quite solved) question here: Calculating event time using gsl_poly_solve_quadratic I'm now looking to calculate the collision response (new linear velocity vector) for the sphere after a collision with a line (rail). The current code I'm extending has two...

Homework Statement Let X ~ norm(5,10). Find P(X>10).Homework Equations f(x) = \frac{1}{δ\sqrt{2π}} e^{-\frac{(x-μ)^2}{2δ^2}} F(x) = P(X<x) = \int_{-∞}^x f(u) du The Attempt at a Solution P(X>10) = 1 - P(X<10) P(X<10) = \int_{-∞}^{10} \frac{1}{δ\sqrt{2π}} e^{-\frac{(x-μ)^2}{2δ^2}} dx =...

Hi guys, first off, thanks for answering my previous question... Now here's another one. I got confused by my school's homework a bit...so there's a car that travels over a humpback bridge with a radius of 45m, so basically it's a semicircle bridge, and so I'm supposed to calculate the...

Homework Statement In a prismatic bar (same cross sectional area throughout the entire length), the load applied to both ends is 100 N causing the member to be in tension. If the cross sectional area of the member is 5 cm2. What is the normal stress in the in kPa? Homework Equations...

Homework Statement Let R be the region bounded by the lines y=1 , y=0 , xy=1 , and x=2 . Let \vec{F} = \begin{bmatrix} x^4 & y^2-4x^3y \end{bmatrix}^T . Calculate the outward flux of \vec{F} over the boundary of R . Homework Equations Green's theorem (normal form): \int_{\partial...

The prices for bananes that a fruit shop would have to pay to keep them in stock have a mean of $1.35/kg and a standard deviation of 18 cents. The owner will not pay more than a certain price, but manages to keep stock 8% of the time. What is the maximum price the ownwer will pay? I found...

Homework Statement Problem 10.36 The bar has cross-sectional areaAand modulus of elasticity E. If an axial force F directed toward the right is applied atC, what is the normal stress in the part of the bar to the left ofC? (Strategy: Drawthe free-body diagram of the entire bar and write the...

Let's consider a stationary ball lying on the floor. The weight of the ball acts downwards and the normal reaction acts upwards. They are of the same magnitude but not of the same type. So normal reaction is the reaction to what, if not weight ?

Homework Statement Air, supplied by a reservoir at 450 kPa, flows through a converging-diverging nozzle whose throat area is 12 cm^2. A normal shock stands where A1 = 20 cm^2. (a) Compute the pressure, p2, just downstream of this shock. Still farther downstream, where A3 = 30 cm^2, estimate (b)...

Could someone suggest me an easy guide to transforming a system of differential equations into normal form around a particular point? As I understand, normal forms are used in border collision bifurcations to define the new set of coordinates around the parameter value \mu _0. By doing this...

I'm studying the hydrogen atom and have this question. Apparently it can be solved without perturbation theory, however I'm having trouble justifying it. Homework Statement 2. The attempt at a solution Avoiding perturbation theory I simply get: E = E(n) - constant*(mh) where m...

Suppose TEM wave in +z normal to a boundary on xy plane at z=0. We know E & H are tangential to the boundary. Let ##\vec E_i=\hat x E##, be the incident wave towards the boundary therefore incident H is ##\vec H_i =\hat z\times \hat x \frac {E_i}{η}=\hat y H##. I have a few questions: 1) How...

My model is a lever on a table top. One arm is horizontal on the table, while the other arm is raised at an angle alpha. I'm assuming the weight of the horizontal lever (F) acts at its center of gravity at a distance f from the pivot, while the weight of the raised lever (W) acts at its center...

Homework Statement Find the equation of each of the normal lines to the curve y = x^3 - 4x that is parallel to the line x + 8y - 8 = 0. Homework Equations Differentiation, y - y1 = m(x - x1) The Attempt at a Solution Well, clearly I start by differentiating y = x^3 - 4x to gey...

Hey all. I'm working on a personal programming project where I'm attempting to simulate (to a small degree) a galaxy. And I have come across a decent 2D density map for a spiral galaxy. This map (array actually) defines a 128x128 grid of values between 0 and 255 representing the frequency of...

So, I'm wondering, Suppose a couple years from now, I've applied to physics graduate schools, but I can't get in anywhere due to GPA issues. My physics GPA is decent, if not outstanding(mostly B+'s and B's so far. I'm hoping I can change those into A's next year, when I'm dealing mainly with...

If there are 2 blocks beside each other and a force is applied to the first block, the first block will push the second block has well. This means that the two blocks are in contact. So why isn't there a normal force drawn perpendicular to the side of the second block if it is in contact with...

This might be a bit philosophical, but is this just from experiment? that for a really really smooth surface, people found that the net force on an incline surface is found to be approximately in the direction normal to the incline plane? (approximately because there's no perfectly smooth...

Here are the questions: Here is a link to the questions: Equation of tangent and normal? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.

Homework Statement A variable line ax+by+c=0, where a,b,c are in A.P (arithmetic progression), is normal to a circle ##(x-\alpha)^2+(y-\beta)^2=\gamma##, which is orthogonal to circle ##x^2+y^2-4x-4y-1=0##. The value of ##\alpha+\beta+\gamma## is equal to A)3 B)5 C)10 D)7 Homework...

I go through major swings of confidence throughout the day. If I get a compliment from someone or some other kind of validation, I'll feel on top of the world, and then some really small disappointment can sink that confidence into almost depression and a feeling of worthlessness. For...

Homework Statement The number of hours of sunshine in one week in a specific resort is assumed to follow a normal distribution with expectation 43 and standard deviation 17. Family A will spend the first three weeks of the summer at the resort. Family B will spend the LAST two weeks of...

This is a very basic problem which you all must have seen somewhere. But recently an itching doubt has come up to me regarding this problem. Problem: A chain lies on a table with some part of it hanging over the edge. Now if the coefficient of friction is μ, then find out the maximum part...

Homework Statement We have two normally distributed random variables: A = N(129, 29.4) B = N(86, 24.0) What is the probability A is atleast twice the size of B? The Attempt at a Solution P(A > 2B | B = b) or something? I think we are supposed to use the CLT somehow but I don't...

I want to come up with an example of a field extension that is not normal, and seems to be difficult. All extension constructed in some obvious way tend to turn out normal.

If G is a group with subgroups H and K, and if H is normal, then HK=KH, right?...Since we know that N(H) = G. However, since H commutes with K, then H must also be contained in N(K), right?...Since N(K) is the set of elements that commute with K...but I was a bit confused, because we know that...

Homework Statement Let us have lines (x+3)/2 = (y+2)/3 = (z-6)/-4 and (x-5)/1 = (y+1)/-4 = (z+4)/1 Find a normal vector to the plane these two lines are on. The Attempt at a Solution I already know you can solve it by s1 x s2 || n ; where s1 = (2, 3, -4) and s2 = (1, -4, 1) but I am not...

The expositions for a normal probability plot (aka normal quantile plot) (in which observed probabilities are plotted against theoretical probabilities, or sometimes the other way around, to get a rough check as to whether a set of data is normally distributed by checking linearity) are not too...

Homework Statement Hey guys. The title says it all pretty much. We need to find the normal mode frequencies of a driven/forced system containing 3 equal masses connected by 4 springs of equal spring constant k. Homework Equations F=m\ddot{x} Spring potential V = 0.5kx^{2}...

Homework Statement I have a question from my homework. My homework is completed, but I've been running some thought experiments lately and I wish to conceptually discuss this. The problem has to do with a hoop rolling down an inclined plane. I had to find the Normal Force using...

Homework Statement ive reduced a problem down to one last part, and where i need the normal and tangential acceleration components of a moving particle. we are given the following: $$a=xi+yj$$ and $$v=ui+zj$$ where a and v are acceleration and velocity and the x,y,u,z are the components. note...

Homework Statement Show that there is no minimum for the normal distribution function e^(-(x-μ)^2/(2 σ^2))/(sqrt(2 π) σ) Homework Equations The Attempt at a Solution I figured I'd take the derivative and set it equal to 0, but then what?

Hi Everyone! I have two normally distributed random variables. One on the x axis, the other on the y axis, like a complex normal random variable. I'm trying to find the pdf of the angle between a fixed point on the x-y plane(let's say point 1,0) and the vector formed by combining the two...

This is (perhaps) a tricky question regarding the moment of normal distribution. Let f(x) be the pdf of normal distribution with mean (-σ^2/b) and variance σ^2, where b is just a constant. The goal is to solve the integral ∫ x^3 f(x) dx integrating from 0 to ∞. I am stuck. Any...

Homework Statement I have a system of two masses m1 and m2 coupled by two springs with constants k1 and k2. If m1 and m2 are equal what would be the normal modes for this system? Homework Equations Equations of motion for the system: \begin{align*} m_1\ddot{x}_1 &=...

Homework Statement A bar with mass m and length l is attached at one end to a string (also length l) and is swinging back and forth. Find the normal modes of oscillation. Homework Equations L=T-U, and the Lagrange-euler equation, I=(1/12)ml^2The Attempt at a Solution So my idea is this. Use...

EDIT:( Sorry I meant for the title of this to say conjugacy classes of subgroups of Z X Z) I have a question.I am trying to figure out, what are all of the normal subgroups of Z X Z? Well, I know that Z has the following subgroups: the trivial group {0}, itself Z, and then aZ, one for each a in...

Homework Statement Tangent to C at point P(2,7) has an equation of y=3x+1. Point Q also lies on C and is perpendicular to the tangent, show that the X-coordinate is [1/3(2+√6)] Homework Equations curve C has equation y= x3-2x2-x+9 dy/dx = 3x2-4x-1 The Attempt at a Solution gradient of...

Hi everyone, I would like to know if this stament is true or not. I have two variables u,v both of them distributed as normal distribution with mean 0 and variance a^2. Is it true that the expected value of uv is a^2 ? Thanks

Homework Statement Perhaps I should say first that this question stems from an attempt to show that in the group \langle x,y|x^7=y^3=1,yxy^{-1}=x^2 \rangle,\ \langle x \rangle is a normal subgroup. Let G be a group with a subgroup H . Let G be generated by A\subseteq G . Suppose...

Homework Statement X is a normal random variable with mean 1, variance 4. 1. Find P( X(X-1) > 2 ) 2. Find a value 'a' for which P(|X| > a ) = .25 The Attempt at a Solution I had no idea how to start 1. For 2, i got this far then got stuck: P(|X| > a) = 1 - P((X-1)/2 <=...

There is a corollary in our textbook that states "Let G be a group of order 12 whose 3-Sylow subgroups are not normal. THen G is isomorphic to A_4." I attached the proof of this corollary and an additional corollary and proposition that was used for the proof. The 2nd last paragraph is a bit...

I know that every action has a reaction, and I understand that applying a force on a surface yields a "force" from that surface to hold it up, and that it's magnitude and direction are equal and opposite, respectively. But conceptually, what is happening? Defining a force in terms of another...

Homework Statement The 2-oz bead P is given an initial speed of 5 ft/sec at point A of the smooth guide which is curved in the horizontal plane. The horizontal force between the bead and the guide has a magnitude of 3 oz at point B. Determine the radius of curvature ρ of the path at this...

Homework Statement Suppose that F = ∇f for some scalar potential function f(x, y) = 1/2(x2 + y2) Let C denote the positively oriented unit circle, parametrized by r(t) = (cos t, sin t), 0 ≤ t ≤ 2∏. Compute the flux integral of \ointF\bulletN ds, where N is the outward unit normal to C.Homework...