Normal Definition and 1000 Threads

Here is the question: I have posted a link there to this thread so the OP can see my work.

Problem: I need to use the Monte Carlo method to generate the mean, variance and kurtosis of the standard normal distribution. It has to be coded in Matlab, so there are two parts to this question: 1) The theory 2) The code Any help on either is appreciated. My attempt: To find $E[X]$ for a...

~~Conceptual Normal Force Question~~ Hello! Suppose there is a meter stick suspended from and parallel to a table. On one end, the meter stick is held up by a piece of string at an angle. On the other end, the meter stick is held up by a metal thing about 10cm tall, simply allowing the stick...

Hi everyone, :) Take a look at the following question. Problem: Determine which of the following quadratic functions \(q_1,\,q_2:\,V\rightarrow\Re\) is positive definite and find a basis of \(V\) where one of \(q_1,\,q_2\) has normal form and the other canonical...

Homework Statement A molecule consists of three identical atoms located at the vertices of a 45 degree right triangle. Each pair of atoms interacts by an effective spring potential, with all spring constants equal to k. Consider only planar motion of this molecule. What are 6 normal modes and...

When normal force isn't "normal"l Homework Statement A box with a certain mass is pulled across a horizontal surface by a rope at an angle. Figure out the components, the friction, the acceleration of the box, when the tension in the rope, its angle, the mass of the box, and mu are given...

What is the expectation, E(log(x-a)), when x is log normally distributed? Also x-a>0. I am looking for analytical solution or good numerical approximation. Thanks

Homework Statement Homework Equations The Attempt at a Solution Solution: Graph: For part a, I understand mathematically why the value of c matters. What I don't understand is how it can possibly matter intuitively. I get that ##\overrightarrow { \nabla }...

Hi everyone, :) Here's a question I found on a Wiki book. Question: The matrix \(T\) is \(5\times 5\) with the single eigenvalue 3. The nullities of the powers are: \((T-3I)\) has nullity two, \((T-3I)^2\) has nullity three, \((T-3I)^3\) has nullity four, and \((T-3I)^4\) has nullity five...

Hi everyone, :) Here's a question that I encountered recently. I would appreciate if you could go through my solution and let me know if you see any mistakes or have any comments. Question: Given a linear transformation \(f:\,\mathbb{C}\rightarrow \mathbb{C}\) with matrix...

Homework Statement Find the equation of the normal line of function f(x,y) = x^2+y^2-1 through points (2,1,4) Homework Equations (x-xo)/f_x = (y-yo)/f_y = (z-zo)/f_z The Attempt at a Solution so... f_x = 2x = 4 f_y = 2y = 2 f_z = ? I don't know how to solve for f_z... here...

What does one mean by normal mode of an object? Why is it 3n-5 for linear particles, 3n-6 for non linear particle where n is the number of particle.

Homework Statement In Fig. 8-28, a small block of mass m = 3.0 kg can slide along the frictionless loop-the-loop. The loop has radius R = 0.80 m. The block is released from rest at point P, at height h = 2.9R above the bottom of the loop. I attatched a picture (a) Find the speed of the...

Hi. I'd like to find the normal modes / harmonics, displayed in a dB - Hz graph, of a given 3D object, namely a wind instrument shaped like a hyperbolic con with holes. I'm trying to perform simulations on Comsol Multyphysics, but I don't know how to do it. Is Comsol the best suited software...

Homework Statement I am studying the solution used for the following question: http://answers.yahoo.com/question/index?qid=20131014213456AA4eCNl And I am unable to understand why normal force Fn = mgcosΘ + PsinΘ Should it not be just Fn = mgcosΘ, When drawing the FBD, the only...

Homework Statement A photo of this problem is available at: http://imgur.com/l5lnI56 (the visual is needed to understand the question) Problem text: A ski jump training hill can be thought of as featuring a near vertical plunge followed by a gradually decreasing (in magnitude) slope...

I have seen different equations for computing the unit normal vector to a surface. What is the difference between the normal vector ##N## of a curve and ##n##. I have seen this formula for a unit normal vector: ##n = \frac{x_1 \times x_2}{|x_1 \times x_2|}##. Which is different from ##N##. For...

Hey! So If I have a stretched string of length L fastened at one end, and I am moving the other end sinusoidally, will a standing wave appear ONLY if I move the other end with one of the normal-mode frequencies of the string? If not, will the resulting wave be a moving wave which is a...

Hi everyone, :) I have very limited knowledge on linear algebra and things like Jordan Normal form of matrices. However I am currently doing an Advanced Linear Algebra course which is compulsory and I am trying hard to understand the content which is quite difficult for me. One of the things...

I have to use this specific heat value to calculate the heat load for designing a machine as refrigerator. Could you please help me to find accurate value. ps. This normal saline is used for medication.

Homework Statement You are pushing four blocks of masses 4, 7, 11, and 17kg positioned next to each other on a frictionless surface. Find the force of contact between the 7 and 11kg blocks when you push the blocks with a 190N force to the left. They are arranged as such: |17||11||7||4|...

I have done 3 experiments. For each one of them, I have repeated the same experiment 100 times. Which gives me three sets of 100 numbers. Experiment 1: for number 30 ---> 100 results Experiment 2: for number 40 ---> 100 results Experiment 3: for number 50 ---> 100 results Basically, I...

Hello! So as you all know the wave-function can be expressed as: y(x,t) = A\cos(kx-\omega t) However, this can be interpreted as both a standing and moving wave. So when do you interpret it as either of those? Are there any special conditions that should be written along with the wave function?

Hi I read at this link http://www.eecs.berkeley.edu/~aude/papers/TRB2012_stat_traffic.pdf something like bus travel times can be normally distributed. Sounds strange to me because normal distribution presumes even negative values Anything I am missing here? Regards

Homework Statement given r(t) = <t, 1/t,0> find T(t) N(t) aT and aN at t = 1 Homework Equations T(t) = r'/||r'|| N(t) = T'/||T'|| aT = a . T = (v . a)/||T|| aN = a . N = ||v x a||/||v|| = sqrt(||a||2 - aT2) The Attempt at a Solution for my T(t) I get <t2, -1 , 0>/(sqrt(1+t4) (I...

Homework Statement Find a nonzero vector normal to the plane -5x -y +z +9 = 0 Homework Equations The Attempt at a Solution so the direction of the vector would be (a,b,c) = (-5,-1,1) I'm not exactly sure what the final form should look like.. is r = ri + tv on the right track...

A 10.0-kg box is placed on top of the 19.0-kg box, as shown in the figure. Determine the normal force that the 19.0-kg box exerts on the 10.0-kg box. i know what the normal force of the 19 kg box. i am having problem setting these kind of problems.

Homework Statement Stick of mass M resting on frictional surface with friction coefficients μk=μs. From the center of the stick at time t=0 a ball of mass m thrown to the right with an angle θ above the horizontal and with speed v0. As a result of the throwing there is an impulse on the y...

when a body is slided or move in a horizontal floor, the Frictional force is directly proportional to the Normal force acting on the body. Is there is any proof (emperically or Theoretically)

I am confused on what the correct way to do this is. In my old physics textbooks, they say that the x component of gravity is responsible for the centripetal force. However, on the internet and for more advanced topics they say it is the x component of normal force that is responsible for...

Hi, I'm having a bit of a problem with a probability question. The question is Let X be a normal random variable with mean \mu and variance \sigma^{2}. Find E[(X -\mu)^{k}] for all k = 1,2,... I'm not really sure what to do and need some help to confirm how to approach the question...

1. Suppose a cube of mass m is lying at rest on a horizontal surface. The area of one face of the cube is A. For the equlibrium of cube no net force acts on it. If we consider the vertical direction then the contact force N should be equal to the force due to gravity plus the force due to...

What is the Unit Normal Vector in Acceleration.\vec{u}_n How would I go about calculating the normal. Wiki and Wolfram Alpha were very vague about calculating the normal of an orbit. I would like to know the normal to the orbit of a mass orbiting a much larger mass not counting any other...

I thought I understood normal forces but I am confused. Could someone explain them to me? What is the normal force on you if you are hanging or climbing up a vertical rope? In a definition, it says that the normal force is perpendicular to the surface, but if the surface is the rope, then the...

Is it normal for university exams to never include some of the material that is in the curriculum? I have some modules that are quite extensive, but about 4 to 5 groups of exercises appear to repeat in the last few years. However, they also ask for students to study about 10 to 15 types of...

Homework Statement Find the normal and shear components (\vec{\sigma}_{n},\vec{\tau}) of the stress vector on the surface ABCD. Given: State of stress at a point \sigma_{xx}=3 \sigma_{yy}=0 \sigma_{zz}=-1 \sigma_{xy}=-\sqrt{2} \sigma_{xz}=1000 Unit normal...

Is ##\frac{ \partial f}{\partial n} = \nabla f \cdot \hat n ## a definition? No article that I found said it's a definition. The term ##\frac{ \partial f}{\partial n}## does not make sense to me, what is ##\partial n##? Also is this correct: \int_v\nabla\cdot (v\nabla u)dV=\int_s (v\nabla...

A hospital would like to determine the average stay for its patients having abdominal surgery. A sample of 15 patients revealed a sample mean of 6.4 days and a sample standard deviation of 1.4 days.How do you display this in a normal curve?? any help would be appreciated. Thanks

Homework Statement X refers to score distribution in Math and Y refers to score distribution in Stat in a certain degree course exam. It is known that X~N(mean = 62, sigma=7) while Y~N(mean = 68, sigma=10). If X and Y are independent, find (i) P[X+Y>120]; (ii) P[X<Y]; (iii) P[X+Y>140]...

Hi guys, I have a repeat exam in 10 days and I have a couple of things which I would appreciate if you would help me with. I have attached the mock exam and my attempt at question 2. I will describe where I have issues below. Homework Statement For the FIRST question, I have the...

Homework Statement (Page 222 number 5) A highway department has enough salt to handle a total of 80 inches of snowfall. Suppose the daily amount of snow has a mean of 1.5 inches and a standard deviation of .3 inches. Approximate the probability that the salt on hand will suffice for...

Homework Statement Let K be an algebraic field extension of a field F, and let L be a subfield of K such that F \subseteq L and L is normal in F. Show that if \sigma is an automorphism of K over F, then \sigma(L)=L. Homework Equations The Attempt at a Solution I've been thinking about this...

This is my first thread on the forum. I'm really glad to have found this wonderful resource. I have a lot of intuition in mathematics and one of my dreams has been to have the same level of intuition in physics. With your help I hope I can achieve that. I was reading an example in Physics...

I was reading this problem on calculating the probability of hitting a certain region on a dartboard. The number of hits the dart thrower will land at a certain radius R on the dartboard is proportional to e^(-R^2). The task is to take a certain portion of a ring (or annulus) on the dartboard...

1) For the normal distribution it seems that the integral of the propability density function from \mu-\sigma to \mu+\sigma is independent of \sigma. I guess that gives kind of a nice interpretation of \sigma. But how do you prove this, when the antiderivative of an exponential with a square...

Homework Statement Metal strips are produced mean length 150cm, standard deviation 10cm. Find probability that length of random strip is: a/ shorter than 165cm b/ longer than 170cm c/ between 145 and 155cmHomework Equations Z = x - μ / σ θ (Z) - θ (z) = average probability (question c) The...

So I'm trying to show that the estimators for the normal distribution by the method of moments are consistent. So to show consistency, I have to : 1) Show E(θ(estimator) = θ (parameter) 2) lim n-->∞ Var(θ(estimator) = 0 So Since there are two estimators in the normal distribution (...

bivariate normal distribution-"converse question" Hello, I have a theoretical question on how to use the bivariate normal distribution. First I will define what I need, then I will ask my question. pics from: http://mathworld.wolfram.com/BivariateNormalDistribution.html We define the...

Normal Operator Proof Homework Statement Prove an operator ##T \in L(V)## is normal ##⇔ ||T(v)|| = ||T^*(v)||##. Homework Equations (1) ##T \in L(V)## is normal if ##TT^*= T^*T##. (2) If T is a self-adjoint operator on V such that ##<T(v), v> = 0, \space \forall v \in V##, then...

If I put a 1 kg mass on the floor, the floor exerts a 10 N force on it, balancing gravity. If I then replace that mass with a 10 kg one of the same area, the floor now exerts 100 N on it. What is it that makes it exert different forces? I know of Newton's third law of opposite and equal...