Unit Definition and 1000 Threads

I am currently working on a project to determine how much weight a mild steel shelving units can support. This is a project for a friend and for my own interest. I am having trouble deciding exactly what is necessary to determine the weight the shelving units will hold. Each shelf on the unit...

Homework Statement Calculate the Radius of Rubidium ion (which adopts sodium chloride structure.), if the density of Rubidium chloride is 2.76g*cm^(-3) and if we assume that the ions touch each other along the sides of the edge of the unit cell. I'm a bit lost here. I assume the...

Hi , if we have a rotating centrifuge at rpm "a" and we have the radius "b" of the centrifuge and then at the side i have a metal ball that weight's "c" I take the formula which you suggested me here F=ma where a=v2/r and out of that I get Newtons, how do i convert them to like pascals? Because...

Hi all! I must compute a derivative with respect to the components of a unit vector \hat{p}^{i}. In spherical coordinates, \hat{p}^{1}=\hat{p}^{1}(\theta,\phi)=\cos\theta \sin\phi I want to express the derivative \frac{\partial}{\partial\hat{p}^1} as a combination of...

Average Cost. A manufacturer has determined that the total cost $C$ of operating a factory is $C=0.5x^2+15x+5000$ where $x$ is the number of units produced. At what level of production will the average cost per unit be minimized? (The average cost per unit is $\frac{C}{x}$) taking C' and...

Homework Statement Homework Equations 1 Liter is 1000cm^3 1 foot is .3048m centi is 10^-2 The Attempt at a Solution convert ft to m 400ft * .3048m/1ft = 121.92m convert m to cm 121.92m is 12192 cm 12192 cm is 12.192 Liter 1 gal = 3.78541 L I look at the appendix but there is no equation...

Are the SI units for pressure N m^2 or is it N m^-2?

I'm not sure where to put this thread, so I just placed it in here. One thing I know is that a Newton is the net force required to accelerate an object with a mass of 1kg at a rate of 1m/s2. Now here's one of my questions: if 1N = what I stated earlier, does 2N = the net force required to...

In statistical mechanics, nearly all the textbooks say that the volume of the smallest cell in the phase space of a N-particle system is h^{rN} where h is the Planck Constant, r is the degree of freedom. Also these books say that this comes from the uncertainty principle. However, the...

what is the unit step response of a high pass RC filter ? I want to calculate using transfer function approach. My solution : Y(s)/X(s) = RCs/(1+sRC) X(s)=1/s Y(s)=RC/(1+sRC) taking inverse laplace transform we should get y(t)=exp(-t/RC) But if we consider Y(s)=RC/(1+sRC) RCsY(s)...

I was just looking at wikipedia's article on ring homomorphisms (http://en.wikipedia.org/wiki/Ring_homomorphism) and I am a little confused. If you look at the definition they give for ring homomorphism, they require only that addition and multiplication is preserved over the homomorphism...

Homework Statement f(z) is analytic for |z|≥1. Let C be the unit circle. Show that the integral \frac{1}{2i\pi}\int_C\frac{f(w)}{wz-z^2}dw is 0 if |z|<1, is \frac{f(z)}{z} if |z|>1 Homework Equations The Attempt at a Solution For |z|<1 case, I tried to write the integral as \frac{1}{z2\pi...

If we set c=G=1, then c=1 leads to L=1/T , the G=1 means that M=L^3/T^2 and combining the two means that M=L=1/T so far so good. But say if I also want \hbar=1 this seems to imply M=T/L^2 but combining this with c=1 which gave the L=1/T now suggests that M=1/L=T . Which seems...

Homework Statement Homework Equations The Attempt at a Solution See the 2 figures attached below. Am I doing this correctly? Is the result I obtained correct? Is there a easier way I could've solved this problem? Thanks again!

Greetings everyone, I am taking a course on elementary condensed matter physics and our textbook is "Introduction to Solid State Physics" by Charles Kittel. I have read the crystal structure from 4 books; however, I am still confused about the definitions such as unit cell, primitive vector and...

The first thing that we should notice is that the leading coefficient $a_n = 1$. I was thinking about considering the factored form of p. I googled, and there is an algorithm called the "Schur-Cohn Algorithm" that is suppose to answer exactly this, but I can't find any information on it or...

I was looking at this example: http://keep2.sjfc.edu/faculty/kgreen/vector/block3/flux/node10.html and was confused between the difference between \hat{}n and \vec{}r Why is the original vector field not given in terms of a unit vector? And what difference does this make? Thanks :)

Hi, I have a curve defined by following parametric equation \begin{equation} \gamma(\theta) = 1 + 0.5 \times \cos (N \theta) (\cos(\theta),\sin(\theta)), 0 \leq \theta \leq 2 \pi \ \end{equation} where N is an integer. x and y coordinate of any point on the curve are simply...

OK, this looks like a differential geometry problem, which it is, but at the end of the day I am trying to figure out why the unit normal and unit tangent vectors to a curve aren't orthogonal, so even if you don't know about DG, please respond. Obviously the two choices for E_1 and E_2...

Is there a quantum of time? What’s the smallest interval of time in which acceleration can place? – on the earth? – on the sun? – on a black hole? A chronon is the time that light takes to cover classical electron radius. The other is the Planck time. But these won't serve my purpose, when I...

Homework Statement Express the 5.2-kN force F as a vector in terms of the unit vectors i, j, and k. Determine the scalar projections of F onto the x-axis and onto the line OA. I have attached an image of the problem. Homework Equations Fx = Fcos(θ) Fy = Fcos(θ) Fz = Fcos(θ)...

Hi everyone, I'm having a little confusion here: I measured a value which is 0.27 nN/nm and I converted it's value as 0.27 N/m. Is this correct or should it be 0.27 nN/nm = 0.27*10^9 N/m Thanks for your help

First, I know nothing at all about this topic, which is why I'm looking for help. I'm interested in building a radio transmitter/receiver like a child locator at home. The difference would be I'd like the receiver to beep rather than the transmitter, if that's even the correct language to use...

Homework Statement Let r=(x,y,z). Find ∇r(hat). Homework Equations r(hat)= (x,y,z)/sqrt (x^2+y^2+z^2) ∇f=df/dx x + df/dy y... The Attempt at a Solution Okay I'm having a complete brain freeze at the moment. I know the denominator is a magnitude but am I still supposed to use the...

Homework Statement Find all values of a such that w=ai+\frac{a}{8}j is a unit vector. Homework Equations unit vector has length of 1. and for a vector v unit vectors would be v/magv The Attempt at a Solution 1=magw=\sqrt (a2+(a/8)2) 1=a2+(a2/64) 64=2a2 32=a2 a=\sqrt{32} i know...

Homework Statement r1=(0m) r2=(2000i + 1000j)m v1=(200j)m/s v2=(200i-100j)m/s Homework Equations tantheta=vy/vx v2^2=v1^2+2ax v2=v1+at x2=x1+v1t+1/2at^2 The Attempt at a Solution Thank you for any help

"The average wavelength of white light is 5.0 x 10-7m. What would this be in nanometers? The textbook answer key stated the answer as 500n but I have no idea how that is the answer. I know that the value of nanometers is 10-9 so I figured you add -7 and -9 to get -16... Thanks,

Homework Statement This is the question Still think that unit conversion isn't important? Here is a widely publicized, true story about how failing to convert units resulted in a huge loss. In 1998, the Mars Climate Orbiter probe crashed into the surface of Mars, instead of entering orbit...

Homework Statement Let P(z)=1+2z+3z^2+...nz^(n-1). By considering (1-z)P(z) show that all the zeros of P(z) are inside the unit disk Homework Equations None given.. The Attempt at a Solution Well (1-z)P(z) = 1+z+z^2+...+nz^n and to find roots I set it to 0: 1+z+z^2+...+nz^n = 0...

Homework Statement A neutrino must pass within about 10^-18m of a quark to have any chance of interacting with it. Thus, the maximum target area that a quark presents to a neutrino is about 10^-36m^2. However, a neutrino moves so quickly and the weak interaction is so weak that...

For doing modal analysis of suction and discharge side of an air-conditioning unit, is it needed to consider the inside refrigerant?

Homework Statement If lightning strikes a tree such that there is the same current through it as there was through the lightning conductor, then a much larger potential difference exists between top and bottom of the tree. Explain why this is so. The Attempt at a Solution Is this...

How do you calculate cost per unit of electricity over a certain time that a generator produces?

Help please...Transmission line parameters in per unit hello there I'm trying to work on a program that converts electrical quantities of transmission line ( R , L , and C ) into per unit system using Matlab the thing is that I'm finding difficulties with the formulas , how I can obtain...

How was a unit of energy first defined? I know we measure energy in units of Joules as named after James Prescott Joule and a Joule is defined as 1kg*(m/s)^2 But I can't find any information on the history of the unit itself, how and when was it first defined, by whom? How was it decided or...

Why unit of torque is not m.N 1.Torque=rFSinθ =>m.N 2. 1 N.m = 1 Joule but 1 N.m in torque ≠ 1 Joule For the above 2 reasons i reckon it should have unit of m.N.

Hello, I have two datasets containing power spectral density data to be compared. One of these datasets is presented in units mm/sqrt (Hz)/degree, and I would like to do some transformation so that data is comparable with the other set, which has units m^2/Hz/rad. Any help on how to do...

Hi guys, what does it mean to observe a filter response to a unit step? The book gives a transfer function and I've recreated it in Proteus ISIS. Now it asks me to simulate a square wave as an input (i used a pulse generator), and then observe a filter response to a unit step, describing the...

I keep reading that a random vector (X, Y) uniformly distributed over the unit circle has probability density \frac{1}{\pi}. The only proof I've seen is that f_{X,Y}(x,y) = \begin{cases} c, &\text{if }x^2 + y^2 \leq 1 \\ 0 &\text{otherwise}\end{cases} And then you solve for c by integrating...

If we have a unit circle within a square s.t. the square touches the circle in 4 places then the biggest gap we can find is just √2 - 1. Doing a similar thing with a sphere in a cube we get √3 - 1 I've heard the n-dimensional analogue is √n - 1. Which is crazy as it means the gap is bigger...

hello, I can't seem to make sense out of amper/meter...one amp flowing throw a wire with a length of 0.5m would be 2A/m ? how does relate to the magnetic field?

For a unit mass sliding down the stationary curve y = f(x) at the point (x, y), we can consider our mass to be sliding down a stationary inclined plane which is tangential to the curve at the point (x, y). The slope of this inclined plane is thus \frac{dy}{dx}(x). For the remainder of this...

The start of a new school year in Ap physics C, and our favorite engineering professors causing students distress! Maybe the champions of the textbook can help me out... = ) Homework Statement 1. Two vectors are given by a = 4i hat - 3j hat + k hat b = -i hat +j hat + 4k hat. Find a) a + b...

Ok, so I'm trying to plot the unit circle using the chebyvhev metric, which should give me a square. I am trying this in MATLAB, using the 'pdist' and 'cmdscale' functions. My uber-complex code is the following: clc;clf;clear all; boundaryPlot=1.5; % Euclidean unit circle for i=1:360...

Homework Statement At a high point in the Earth’s atmosphere, He2+ ions in a concentration of 2.8 x 10^12 m^-3 are moving due north at a speed of 2.0x10^6 m/s. Also, a 7.0 x 10^11m^-3 concentration of (O2)- (dioxygen -)ions is moving due south at a speed of 7.2 x 10^6m/s. Determine the...

I want to show that if the complex variables ζ and z and related via the relation z = (2/ζ) + ζ then the unit circle mod(ζ) = 1 in the ζ plane maps to an ellipse in the z-plane. Then if I write z as x + iy, what is the equation for this ellipse in terms of x and y? Any help would be...

how a step function has frequency content in it? thanks

Hello again. First off, I wasn't sure how to say this in the title but I'm not taking the inverse Laplace transform of a unit step function. I'm taking the Laplace transform of something that comes out to the unit step function. I have this question, which is a similar version of the...

I was reading a link i found here on physicsforums called "The relativistic rocket". There was lots of calculations of the required fuel for certain distances and such. However, I understand that time→0 when our velocity v→c. And that will mean we travel a larger distance for a shorter...

I would like to inquire whether there has been any recent work on representing matrices in unit vector notation? Thanks in advance!