Normal Definition and 1000 Threads

Homework Statement A particle with mass m is trapped inside the infinite potential well: 0<x<L : U(x) = 0 otherwise: U(x) = ∞ ψ(x,t=0) = Ksin(3∏x/L)cos(∏x/L) What energies can be measured from this system, what are the probabilities for these energies ? Homework Equations Schrödinger...

Homework Statement Calculate the frictional force, normal force and coefficient of friction for an 0.2kg object that is lying on a 35 degree incline. Homework Equations Ff= u x Fn F= m x a The Attempt at a Solution I managed to get FN= m x a x cos# = -9.81 x 0.2 x cos35 = 1.61...

A formula for finding the normal vector for curvature is: N=(dT/ds)/(||dT/ds||) Where dT=change in tangent vector ds=change in distance travelled Another fromula was: N=(dT/dt)/(||dT/dt||) What's dt ? Is it the same as ds? I don't think so cause the course notes said that...

Dear Users, For normally distributed random variables x and y's p.d.f.: \frac{1} {\sqrt{2\pi \sigma_x^2}}\exp\left\{- \frac{(x - \mu_x)^2}{2 \sigma_x^2}\right\} and \frac{1} {\sqrt{2\pi \sigma_y^2}}\exp\left\{- \frac{(y - \mu_y)^2}{2 \sigma_y^2}\right\} What will be the p.d.f. of...

Homework Statement http://www.xtremepapers.com/CIE/International%20A%20And%20AS%20Level/9709%20-%20Mathematics/9709_s05_qp_6.pdf question no. 6 part ii (Safety regulations state that the pressures must be between 1.9 − b bars and 1.9 + b bars. It is known that 80% of tyres are within...

D is a set of all points (x,y) in R2 distinct from (0,0). I have the funtion f: D --> R which is defined by: f(x,y) = (2xy)/(x2+y2 Im asked to find the equations (in plural) of the tangelnt plane and the normal line to the graph of the function at (1,2) My attempt: I use the tangent plane...

I'm trying to derive an expression for the normal forces on a cars tyres traveling around a circular banked track. Initially I was going to assume the centre of gravity was located longitudinally and laterally centre between all four tyres (so front and rear had the same forces on them). Also...

Let $H\leq G$, where $G$ is some infinite group, and there exists some $g\in G$ such that the set $\{g^n: n\in\mathbb{Z}\}$ is a transversal for $G/H$. Then is $H$ normal in $G$? I suspect not. However, I cannot seem to find a counter-example. (By "a transversal for $G/H$" I mean that 1)...

Homework Statement Homework Equations The Attempt at a Solution

Homework Statement Now, G is a finite group, and P is a Sylow P-Subgroup of G, and H is a subgroup of G with P≤H≤G. So if P is normal in H, and H is normal in G, then P is normal in G. Homework Equations The Attempt at a Solution I know I want to show that gpg^-1 is contained in P...

I am trying to analyse a past series of numbers that flucuates between 107&210 with a normal frequency distribution of mean 162. What is the way to model and project short term future range for trendless but cyclical type of time series?

I have two multivariate normally i.i.d random variables, x and y, that are size n vectors. Let us assume for simplicity that their variances are 1. From these random variables, I form two vectors that contain their means, and denote these mx and my. I know that if mx = my, then W = (mx -...

Homework Statement The small mass m sliding without friction along the looped track shown in the figure is to remain on the track at all times, even at the very top of the loop of radius r. http://session.masteringphysics.com/problemAsset/1057653/6/GIANCOLI.ch08.p090.jpg A)In terms of...

Hey guys. I'm sure some of you are aware of how to analytically integrate e^(-x^2) dx from - infinity to infinity using polar coordinates. I have taken that logic and showed that the integral of the normal distribution( not necessarily standard) integrates to 1 over the entire domain...

Physics lab normal force please help! A 1000-kg car moves at a maximum speed so that it does not skid off the 50-m radius level track. If the coefficient of static friction between the road and wheels is 0.80. What is the maximum speed? Assume that the gravitational constant is 10.0 N/kg =10.0...

Homework Statement Given a parameterized surface: C(u,v) = (3 cos u sin v, 2 sin u sin v, cos v) 0<u<2pi, 0<v<pi I have to find a normal vector to that surface. Homework Equations The Attempt at a Solution So tangent vectors can be Tu = (dx/du, dy/du, dz/du) and Tv =...

Hello, I understand the tangential shear stresses (or forces) acting on a fluid element due to friction between moving fluid layers, but I can't imagine how viscosity might cause a normal force (on a fluid element)...explain please!

Hi all! My question is the following. Suppose we have two normal topological spaces X and Y and we have a continuous map from a closed subset A of X to Y. Then we can construct another topological space by "glueing together" X and Y at A and f(A). By taking the quotient space of the disjoint...

Hi Physics Forum! I hope this is the right section... I couldn't find a section on statistics. This is a rather easy question but I can't seem to get the answer that the answer key says! Average Life expectancy μ=72 standard Deviation ( in years ) δ=5 The question: Recent studies have...

Homework Statement Find average value of Normal Acceleration from the information given. (See the picture) Homework Equations a^{→}_{ave}= Δv^{→}/Δt a_{t}=Δv/Δt The Attempt at a Solution I took the difference of the given angles in radians and divided it twice by Δt and get...

TITLE: Normal distributions (sorry) Question 1: Working: Now the answer for sigma i got correct, but μ i got incorrect for some reason. Could anyone explain where I've gone wrong for μ? Question 2: Workings: All i need help is with part c and d: for c) i done 1 - 0.6463 to get the...

Homework Statement A person who normally weighs 200 lbs is standing on a scale inside of an elevator. The elevator is moving downwards at a constant speed of 7.0 m/s and then begins to slow down at a rate of 4.9 m/s^2. Before the elevator begins to decelerate, the reading of the scale is...

Homework Statement Find the Jordan form and use it to find the matrix exponential. Homework Equations The Attempt at a Solution Let A =\begin{bmatrix} -3 &-1 &-1 &-1 \\ -1 & -3 & 1 & 1 \\ 1 & -1 & -5 & -1 \\ 1 & -1 & -1 & -5 \end{bmatrix}...

Need help calculating friction and normal force for "Measuring Friction" Lab Hey guys, I'm not great at physics and have a lot of work ahead of me so I could use some help. The lab setup is a wooden block sliding on a wooden surface. There is a weight attached to the block by a string that's...

Suppose I know that the diastolic blood pressure of my 30 patients is normally distributed with the same mean and standard deviation. Then the odds of one patient having a diastolic blood pressure is x higher than the others is the probability that the observed value of a normally distributed...

Homework Statement Prove that if p is a prime and G is a group of order p^a for some a in Z+, then every subgroup of index p is normal in G. Homework Equations We know the order of H is p^(a-1). H is a maximal subgroup, if that matters. The Attempt at a Solution Suppose H≤G and...

Homework Statement This is a two part problem A) Find a vector normal to the plane at (2,1,7) B) Find a vector normal to the plane tangent to the paraboloid at (2,1,7) Homework Equations Plane: z = x + y +4 Paraboloid: z = x^2 +3y^2 The Attempt at a Solution I'm not sure where...

Homework Statement Prove: If H is a subgroup with finite index in G Then there is a normal subgroup K of G such that K is a subgroup of H and K has index less than n! in G. Homework Equations Note: |G:H| represents the index of H in G |G:H| is the number of left cosets of H in G, ie...

Homework Statement If t = pi/2, then that would equal 2, but they don't say that t = pi/2 so how do they get 2? Maybe since it's circular motion t = pi, that would work too, but I want to be sure before i move on.

Normal distribution modified by "potential" For a random process the distribution if described by a gaussian distribution. But if the process has components that throw off the normal distribution, can any distribution be described by a gaussian distribution with another function, call it a...

Homework Statement Question: "Find the unit tangent, normal and binormal vectors T, N, B, and the curvature of the curve x = 4t, y = -3t^2, z = -4t^3 at t = 1." Answer: T = 0.285714285714286 i - 0.428571428571429 j - 0.857142857142857 k N = -0.75644794981871 i + 0.448265451744421 -...

Why is it that the normal force always point perpendicular to the plane? If I imagine the ground as made up of a bunch of particles I find it hard to see, why they should necessarily direct their forces perpendicular to the plane. Consider as a classical example a box sliding down a slope. The...

Just to help my understanding... 1) Can you have an abelian subgroup of a group which isn't normal? 2) Can you have a normal subgroup which isn't abelian? Cheers!

Homework Statement If I have a time series model x_1 = my + epsilon_1 x_i = my + a(x_{i-1} - my) + epsilon_i epsilon_i are iid standard normal. Can I then say that y = a_1 x_1+a_2 x_2 + ... a_n x_n is multi normal? The Attempt at a Solution All the x-es are normal...

Hi I have a set of observed data from time intervals like 4,5,... I want to fit this data to normal distribution. Is there any normalization process I can make to change them from integers to real numbers as long as normal distribution is continuous? Regards

Hi, I have a question If X1,X2,...,Xn are independent random variables having chi-square distribution witn v=1 and Yn=X1+X2+...+Xn, then the limiting distribution of (Yn/n) - 1 Z= --------------- as n->infinity is the standard normal distribution. sqrt(2/n) I know that Yn has...

Homework Statement How do you add the normal forces together after you derive the x and y component? Homework Equations Normal force = m*g*sinθ (y component) Normal force = m*g *cosθ (x- component) The Attempt at a Solution Bottom line is I'm trying to get the Net Force...

I have a mixture of multivariate normal distributions, and I want to compute the integral with the first element of the input vector varying between specified limits, and the other elements varying from -infinity to +infinity. See attached pdf for equations. I've done it numerically but would...

Homework Statement Find two unit vectors that are normal to the plane determined by the points A(0,-2,1), B(1,-1,-2), and C(-1,1,0) I found the cross-product of the two position vectors then i got 8i+4j+4k then i divided that by the magnitude to get the unit vector but how do i find the other...

Which is true/false? When a force is called a "normal force", it is: A force that is always equal to the weight of the object. A force that is perpendicular to the surface of the Earth at any given location. A contact force perpendicular to the contact surface between two solid objects...

Homework Statement Let H be a subgroup of group G. Then H \unlhd G \Leftrightarrow xHx^{-1}=H \forall x\in G \Leftrightarrow xH=Hx \forall x\in G \Leftrightarrow xHx^{-1}=Hxx^{-1} \forall x\in G \Leftrightarrow xHx^{-1}=HxHx^{-1}=H \forall x\in G...

I am trying to find a succinct definition of normal coordinates and normal modes - relating to numerous coupled harmonic oscillators. What exactly do the normal coordinates describe about these coupled harmonic oscillators? I know that for normal modes, all parts of the system move with...

So in class today we were talking about Normal Force, and I was really confused on one diagram. Here is a link about the question, but I don't understand why n<mg because if it is less than mg wouldn't that make it go through the earth? not sure but help understanding would be great...

Homework Statement Lets say we have some data which we using the method of the least squares regression can express a linear regression model. I would like to know if this data generelly will be normal-distributed if it can be expressed by a linear regession model? and if so any way to...

Homework Statement The equation is here: http://www.wolframalpha.com/input/?i...E2%2F%28.98%29 You are trying to solve for the angle in this case x wolframalpha gave a solution to this problem but it did not show the steps and I can't use that on the test. So can anyone please do the...

Ok, I've been stewing on this problem for a couple weeks now, and it's primarily due to my lack of practice with vectors, but I'm learning how to work with 3D computer graphics and trying to determine when an object hits a plane. Given the normal of the plane N=[nx,ny,nz] and the point at the...

Homework Statement Given a bivariate normal distribution with E(x1)=4 and E(x2) = 6 and Var(X) = [3 2.5] [2.5 7] Find P(2*x1>x2) Homework Equations The cdf of this bivariate...

hey Gonna get straight to the point. I need to establish the probability difference between two probabilities p_1 and p_2 at 95%. Its the two probabilites that a cabin hook will hold for a certain force (25kN). two samples, each with sizes "the originals" n_1=107, "cheap pirated ones"...

Say we have a roller coaster, and we want to calculate the speed the roller coaster can go at barely making the loop. Normally, the equation would be n+w=m*v^2/r, but why do we set normal equal to zero when we're solving for the minimum speed? Where does the normal come from on top of the roller...

Astrological "evidence" produced by looking at the tails of a normal distribution I just ran across this on a large news aggregation website, so I'm sure some people here might have seen it as well. http://www.inquisitr.com/173752/jail-time-predetermined-by-astrology-signs-says-police-study/...