Normal Definition and 1000 Threads

Hi, The question I have is not for a numerical answer but for clarification. Some of the questions involving torque/rotational equilibrium describe a person standing on a plank. I know that the gravitational force of the person on the plank needs to be considered for translational and...

Homework Statement The two cars A and B enter an unbanked and level turn. They cross line C-C simultaneously, and each car has the speed corresponding to a maximum normal acceleration of 0.94g in the turn. Determine the elapsed time for each car between its two crossings of line C-C. What is...

Homework Statement Simple proof on why ∇∅ is normal to surface of ∅(x,y,z) = constant Homework Equations The Attempt at a Solution

I just finished Chemistry I last semester and am taking Chemistry II this semester. These are the "101" type prerequisite Chemistry courses required for the AA. Although I earned a 98 in Chem I (with a class average of 75), I still feel like I didn't learn much. To sum it up, here are the...

Homework Statement A motorcyclist travels around a curved path that has a radius of 450 ft. While traveling around the curved path, the motorcyclist increases speed by 1.10\frac{ft}{s}. Determine the maximum constant speed of the motorcyclist when the maximum acceleration is 7.00...

I'm currently in my first abstract algebra course, focused on sets, groups, arithmetic modulo, rings, fields etc. I've never taken an abstract course before. I've taken: Pre-calc Calc 1-2 Linear Algebra Advanced Applied Linear Algebra so the concept of abstraction is very new to me; I...

Homework Statement I've been having a little bit of trouble answering this question: "An 8.0 kg wooden sled is pulled over the snow by means of a rope that makes an angle of 40° with the horizontal. If the rope has a tension of 70.0 N, what is the normal force acting on the sled?"...

Homework Statement Homework Equations The Attempt at a Solution When i do the matrix multiplication of the 2x2 and 2x1 matrix, I get 2 conflicting solutions that don't match at all! So which one do i take to find ratio of X and Y?

Homework Statement If the gravitational acceleration at Earth's surface is given by: g = GMe/Re^2, show that the period of rotation of a spaceship needed to make an astronaut feel the same normal force on the ship that they would feel on Earth, when it is given by T = √[(4pi^2)(Rs)(Re^2)/GMe]...

Homework Statement A thin uniform rod of length 2b is suspended by two vertical light strings, both of fixed length l, fasted to the ceiling. Assuming only small displacements from equilibrium, find the Lagrangian of the system and the normal frequencies. Find and describe the normal...

Homework Statement Variable A has mean 55 and variance 9, variable B has mean 65 and variance 25. If A and B are normally distributed, find P (B > A) Homework Equations z = (x - μ) / σ The Attempt at a Solution Can this be solved? What is the meaning of P (B > A)? The probability...

Homework Statement Given: Standard Deviation = 500 Homework Equations How I calculate the μ (mean) using standard deviation for a norma distribution. Thanks. The Attempt at a Solution

With a 5W FM transmitter and a normal dipole antenna , to what range can I transmit. To be more specific, what will be the radiation pattern like (Can I get signal uniformly as in a circle where the center is antenna). Using which antenna, can I achieve maximum range omnidirectionally...

P(x=mean) of normal PDF with low sigma -- not allowed? About the normal probability distribution: with formula P(X=x) = (1/(σ*sqrt(2π))*exp(-(x-μ)2/2σ2), what happens when you look at P(X=μ) if σ<(1/sqrt(2π))? You get P(X=μ)>1, an absurdity. What is going on? Second question is one about...

Hi, I'm studying Small Oscillations and I'm having a problem with normal modes. In some texts, there is written that normal modes are the eigenvectors of the matrix $V- \omega^2 V$ where V is the matrix of potential energy and T is the matrix of kinetic energy. Some of them normalize the...

Ok, so 2 objects in contact with one another exert a normal force pair between the 2, but it is my understanding that they never 'touch' each other, rather, it is the repulsion of the outer electrons that create the electromagnetic 'normal' force. QUESTION 1: Is there physical space betwen the...

A bit confused about the operation of normal forces. When does a normal force act due to some surface on an object? When the object touches the surface or when the object actually applies a force on the surface? The reason I ask this is because I am confused about normal forces...

Homework Statement passengers cannot have a normal force equal to 0 or greater than 4 times their weight. What are the heights H1 and H2. Coaster starts at H1 and and ends at H2. H1>H2 and there is a low point between the two hills defined as zero height. The radius of the curve at the...

Homework Statement See attachment Homework Equations eAB=(Lf-Lo)/(Lo) The Attempt at a Solution Ok, this is not for HW. I am preparing for a mechanics of materials class next semester. I don't understand when CB goes through the 0.3 degree arc, they say the height is still 300mm. Shouldn't...

In my high school physics class, we are doing an experiment where we go up a flight of steps, record the time it takes, and calculate the work done in the vertical direction. I understand everything (I am a pretty bright student) except one part that I simply cannot wrap my head around. To...

Homework Statement Suppose that a blast wave, which might have been initiated by an atomic bomb explosion, is traveling through air at standard atmospheric conditions with a speed of 60,000 m/s find change in ( pressure , temperature , stagnation pressure , velocity ) produced by the wave...

Homework Statement PM and PN are perpendiculars upon the axes from any point 'P' on the ellipse. Prove that MN is always normal to a fixed concentric ellipse Homework Equations The Attempt at a Solution I assume point P to be (acosθ, bsinθ) The eqn of line MN is then given by...

Homework Statement Z is a 2x1 multivariate gaussian random vector, where Z = (X Y)^t , X,Y are real numbers, with mean zero and covariance matrix \Gamma which is a 2x2 matrix whose entries are \Gamma_{1,1} = 1 \Gamma_{1,2} = \alpha \Gamma_{2,1} = \alpha \Gamma_{2,2} = 1...

This is not really a homework question, but I've come across this while preparing for a test Homework Statement Let f:U \subseteq R^n -> R^m be a function which is differentiable at a \in U, and u \in R^n It is then stated that it is clear that: lim_{t \to 0}...

Homework Statement Here is the problem along with the solution: I am confused about part (a). Why is it that the area used is 2*0.008*(0.036-0.016). If you draw a cross section at just one of the holes, wouldn't that give you the max average stress? So the area used should instead be...

Hi there, I've got a conceptual question about the normal force as applied to rotational motion. Suppose you have an object like a uniform disk. If the disk were set up so that its axis of rotation were about its centre of mass, it would just sit there and the normal force would be equal to...

Homework Statement 1. Show that X is independent of Y- \alpha X where |\alpha| < 1 2. Find the joint distribution of F = X and G = X + Y X,Y,G,F are random variables Homework Equations The vector W = (X, Y)^{t} is a 2x1 multivariate Gaussian random vector with zero mean...

The title, basically. If we're at a temperature below the critical temperature (let's just say for a Type 1 superconductor) and an applied magnetic field less than the critical magnetic field, it will be in the superconducting state. But if we increase the field beyond the critical point, it...

Hi, Suppose we have a fellow on a ferris wheel. Would the normal force be greater on the top or at the bottom of the ferris wheel? I'm thinking that it would be greater at the top, or am I wrong? Thanks,

I was wondering if acceleration (a) is the speed in which speed changes how come it can b higher than 0 and still v=0? like when there is a force pulling from the other side, the body won't move but since there is force there is acceleration. So which is which? Does the tangential...

Normal Matrices Examples (URGENT) I need to produce 2 x 2 normal matrices A and B such that A + B is not normal. I have proven that AB is normal if AB = BA using the Householder matrix form. But I can't find a form for A + B failing to be normal. A matrix A with entries a, b, c, d is going...

There are two types of zeeman effect, one normal and the other one anormal, but why are they called so? I mean what is so normal about the normal zeeman effect and what is so anormal about the anormal zeeman effect??

http://imgur.com/SnHyP What are the mathematical steps and assumptions to reach the conclusion that length(ab) ≈ dx + ∂u/∂x*dx ? If you consider the the squares of the gradients to be negligible, you still have a square root and multiplication by the constant "2". What other assumptions do...

http://imgur.com/SnHyP What are the mathematical steps and assumptions to reach the conclusion that length(ab) ≈ dx + ∂u/∂x*dx ? If you consider the the squares of the gradients to be negligible, you still have a square root and multiplication by the constant "2". What other assumptions do...

Hi guys. Please look at the uploaded picture. Normal stress is difined as: σ= P/A. And the Maximum normal stress σ = P/ (b*h/cos(θ)) ?? The right answers should be σAB= 97,7 MPa and σBC = -66,5 MPa. But how do I calculate it? What I have tried: Force AB: 40* sin(60deg) = 34,641 kN...

Homework Statement Two horizontal frictionless rails make an angle θ with each other. Each rail has a bead of mass m on it and the beads are connected by a spring with spring constant k and relaxed length=zero.Assume that one of the rails is positioned a tiny distance above the other so that...

Homework Statement Hi everyone! first post here :) Basically, the question is as follows: Consider a hydrogen fluoride molecule (atomic mass of H is 1g/mole and of F is 19 g/mole). 1. Write the energy of the system in terms of the displacements of both atoms. There are other questions...

Homework Statement Two equal masses (m) are constrained to move without friction, one on the positive x-axis and one on the positive y axis. They are attached to two identical springs (force constant k) whose other ends are attached to the origin. In addition, the two masses are connected to...

Homework Statement 1000 independent rolls of a fair die will be made. Compute an approximation to the probability that the number 6 will appear between 150 and 200 times inclusively. If the number 6 appears exactly 200 times, find the probability that the number 5 will appear less than 150...

how can you tell if the frictional force is great enough to keep a car turning a curb in circular motion based on the coefficient of friction and the normal force?

Where does the normal line to the ellipse x2-xy+y2=3 at the point (-1,1) intersect the ellipse a second time?So I took the derivative of the equation to get: y'=(2x-y)/(x-2y) Then I put (-1,1) into the equation, to get a slope of 1. So, for the normal line I got a slope of -1, which has the...

Homework Statement You exert a force of 131 N [30° below horizontal] onto a 12.6 kg lawn mower, What is the force of gravity and normal force on the lawn mower?Homework Equations Fg= m × g FA (y component) = Sin30° × FAThe Attempt at a Solution The force of gravity is equal to the force of...

Lets assume that liquid superconductors exist. Now I place a magnet above a pool of the liquid. Now will the surface of the liquid remain level or will it appear to have dent in it. I am not sure I kind of back and forth in my head.

Homework Statement Generalize: For arbitrary 0 < p < 1, show that the method giving a and b produces the minimum length interval. Hint: It might be helpful to use local extrema for the inverse function of the distribution function. Homework Equations The method is is talking about is...

Homework Statement This is just a more generalized question, and not really about a specific value. The question was regarding torque, and had a man standing on a ladder like so. The only force (exerted by the man on the ladder) that provided torque was indicated to be mg, but I don’t really...

Hello Forum, If a bike is negotiation a curve, the static friction force will supply the centripetal force F_c. If we go too fast and the friction is not enough we skid along the tangent. There are two forces: the weight W=mg pointing down, the normal (contact) force N pointing up and...

Homework Statement Find all points on the surface at which the tangent plane is horizontal z=x3y2 Things I know: Tangent plane is horizontal then therefore the normal must be vertical in order to be perpendicular. Dot product of the tangent plane with normal is = 0 Normal...

[FONT=arial][FONT=arial]Using the standard normal table in your lecture notes, calculate to four decimal places[FONT=arial] Table file:///Users/manukumarindia/Desktop/Screen%20Shot%202012-10-29%20at%2011.12.15%20AM.png Work done so far. [FONT=Helvetica]If X ~ N(22,4), z = (x - 22)/sqrt(4)...

I have an incline A that is very steep reaching a vertical height of h and another one B which is less steep with the same vertical height. So using the work energy theorem: in A, KE+work done against friction=mgh so the work done against friction and initial KE is equal to the gain in...

Homework Statement Question - On a statistics examination, the mean was 78 and the standard deviation was 10. (assume normal distribution). a) Find the standard scores of two students whose grades were 93 and 62, respectively. b) Determine the grades of two students whose standard...