Components Definition and 911 Threads

If we have a positive integer, how many ways can this number be written as a sum of its components? By components, I mean all numbers less than that number. For example, 5 has 6 ways to be written; 5x1, 3x1+2, 2x2+1, 2x1+3,1+4 and 2+3. In digits form; [11111, 1112, 221,113, 14, 23] So there are...

Homework Statement The truss supports a sign board as shown in the figure. Calculate the reactions at A and the force in the member FG produced by the horizontal wind load of 60lb per vertical foot of a sign. Homework Equations ΣFx=0 ΣFy=0 ΣM=0 The Attempt at a Solution Everything is right...

In a source-free, isotropic, linear medium, Maxwell's equations can be rewritten as follows: \nabla \cdot \mathbf{E} = 0 \nabla \cdot \mathbf{H} = 0 \nabla \times \mathbf{E} = -j \omega \mu \mathbf{H} \nabla \times \mathbf{E} = j \omega \epsilon \mathbf{E} If we are looking for a wave...

Homework Statement What is the tension in a pendulum? Is T=mgcos(theta) or is T=mg/(cos(theta)) ? and is the x component of tension is mgsin(theta) and this is the restoring force? Homework Equations Fnet=ma Fg=mg The Attempt at a Solution Maybe it depends on the problem given? But I am...

Hello, My question is about using vector components to find a force in a particular direction. I already have the answer, I just don't understand it and would like an explanation if anyone has one. If I have two vectors with radial velocities (in this case it's measurements of ocean current...

Why not work with the complete signal, instead of breaking it into in-phase and quadrature components?

I have a Dicom Image that is interpreted as an array. Each cell is a pixel. Each pixel has a value. I want to find the vector components (x,y,z) of a pixel. Specifically, I want to find magnetic field vectors for each pixel. The image is for H1 atoms. Freq = 297, B0 = 3. How would you do this...

I am looking to find a 5v to ≈70v dc-dc converter in the 1w range or the equivalent transformer + diodes. This is for a bio stimulation device and I need a high voltage and low amperage. However, not having spent years researching and buying electrical components, I'm a little uncertain where...

This has been in the back of my head during a course in Mathematical Physics. In for example cylindrical or spherical coordinates, we have one or two unit vectors describing position (er, for example), their directions in a Cartesian system the function of three variables. But we also have e.g...

Homework Statement (I roughly translate the problem statement from German) Given the vectors a = (1,-2,3) and b = (1,1,1), divide the vector a in two components a1 (parallel to b) and a2 (perpendicular to b). Homework Equations In a previous question of the problem, I found that: a.b = 2 a x...

Homework Statement Two rockets leave their space station along perpendicular paths, as measured by a flight controller on the space station (see figure). The flight controller records the speeds of Rockets 1 and 2 to be 0.6 c and 0.8 c respectively. What is the velocity of Rocket 2 as measured...

Hi I downloaded visual studio 15 and as i saw some of its components need to be installed I tried to install them but it seems that its not compatible with my internet download (20kb/s download breaks after few minutes) So is there any way i can download them from microsoft and install them...

Hello. I'm studying quantization of electromagnetic field (to see photon!) and on the way to reach harmonic oscillator Hamiltonian as a final stage, sudden transition that the Fourier components of vector potential A become quantum operators is observed. (See...

Hey! I'm reading a book Intermediate Physics for Medicine and Biology In it, there is a section that is describing shear forces and it says this as a side note: In general, the force F across any surface is a vector. It can be resolved into a component perpendicular to the sur- face and two...

Source: http://gmammado.mysite.syr.edu/notes/RN_Metric.pdf Section 2 Page: 2 Eq. (15) The radial component of the magnetic field is given by B_r = g_{11} ε^{01μν} F_{μν} Where does this equation come from? Section 4 Page 3 Similar to the electric charges, the Gauss's flux theorem for the...

Hello, I am having trouble finding the direction of the resultant of this statics homework problem. The picture uploaded is exactly how it is shown in my book. The problem states: Homework Statement For the forces shown, S = 3.81 kip, T = 4.73 kip, and U = 3.65 kip. Determine the resultant...

Homework Statement This is really 3 questions in one but I figure it can be grouped together: 1. The vector A = i xy + j (2y-z2) + k xz. is in rectangular coordinates (bold i,j,k denote unit vectors). Transform the vector to spherical coordinates in the unit vector basis. 2. Transform the...

Homework Statement Consider a frame that is moving with velocity v in the positive x-direction. An observer in this moving frame measures the velocity of the particle in the x- and z-direction, u_x' = 0.9c, u_z'=0 a) What is the maximum velocity of the particle in the y-direction u_y' measured...

Homework Statement Three charged particles are placed at each of three corners of an equilateral triangle whose sides are of length 2.7 cm . Two of the particles have a negative charge: q1 = -6.0 nC and q2 = -12.0 nC. The remaining particle has a positive charge, q3= 8.0 nC . What is the net...

Homework Statement Is there a place where I could find every component of every physics formula explained? I know basic stuff like that a line over a variable means average. But, I have no idea what the various subscripts and superscripts on the formulas mean. Thanks for reading Homework...

Let us suppose a rod is inclined on the ground such that its middle point is supported by a peg. It is a uniform rod and the point where it touches the ground is A, mid-point (also the centre of gravity) is C. The rod is inclined at angle theta with horizon. So, we can divide the components of...

Hi everyone, So I'm going through a chapter on dual spaces and I came across this: "A key property of any dual vector ##f## is that it is entirely determined by its values on basis vectors. ## f_i \equiv f(e_i) ## which we refer to as the components of ##f## in the basis ##{e_i}##, this is...

Hello, a derivation of the lorentz transformation for an arbitrary direction of the relative velocity often makes use of writing the spatial position vector of an event as the sum of its component parallel and perpendicular to the velocity vector in one inertial frame and then transforming both...

I have managed to work out parts a and b of Exercise 13.7 from MTW (attached), but can't see how part c works. I can see how it could work in (say) the example of taking a radar measurement of the distance to Venus, where we have the Euclidian distance prediction and the result of the radar...

Hi there, I recently attended a physics demonstration (Lightning show at Boston Museum of Science, my favorite exhibit obviously), where the educator argued that the reason she could safely sit in a Faraday Cage while lightning was striking said cage was the skin effect. As I understand it...

Homework Statement I'm having trouble understanding why we solve vector components (i and j, or the horizontal and vertical legs) like a right triangle? An example would be a 5-4-3 triangle. If 5 N was the force vector I am solving for then I would end up with 4 N in the horizontal direction...

Homework Statement Hello, I just started my summer class "Applied Linear Algebra I" Last math class of my under-grad and its been 1 year since I've last taken Calc3, so I'm trying my best to get back into the groove...anyways. Our first topic we are discussing in class is vectors. [1] This...

Homework Statement The Particle moves in the plane in a such a way that its polar equation of motion is ## \vec{R}=t\vec{i}+(t^2+1)\vec{j}##. a)What are its normal and tangential components of accelaration any time t ? b)Whats the curvature of path any time t ? Homework...

Homework Statement Let ##u_1,u_2,u_3## be a basis and let ##v_1=-u_1+u_2-u_3## , ## v_2=u_1+2u_2-u_3## , ##v_3=2u_1+u_3## show that ##v_1,v_2,v_3## is a basis and find the components of ##a=2u_1-u_3## in terms of ##v_1,v_2,v_3## Homework Equations For basis vecor...

"A system is a set of interacting or interdependent components forming an integrated whole." Hi, above definition is from Wikipedia, for system and prepared by referring to Merriam-Webster Dictionary. I would like to discuss some concept in that definition because they are very foreign to...

Just wondering if I've forgotten a rule here, or there is some new terminology I can learn. We know 0/x when x > 0, is equal to 0. x/0 is undefined..since we "blow up" dividing any value by a value that is more than infinitely small...by zero. We say that 0/0 is also undefined. We choose to...

Hey there, I have a quick question, and it can be answered with a reference to a book chapter of article. If I'm given the z component of the electric field inside a resonant cavity, and furthermore, if it's set that Bz = 0, how do I determine the other components for both E and B?

Homework Statement If matrix ## C = \left[ {\begin{array}{c} A \\ B \ \end{array} } \right]## then how is N(C), the nullspace of C, related to N(A) and N(B)? Homework Equations Ax = 0; x = N(A) The Attempt at a Solution First, I thought that the relation between A and B with C is ## C = A...

Hey all, I'm just starting into GR and learning about tensors. The idea of fully co/contravariant tensors makes sense to me, but I don't understand how a single tensor could have both covariant AND contravariant indices/components, since each component is represented by a number in each index...

So it seems straightforward to me that if time dilated, then so would size, mass and energy, but I don't know how to prove that mathematically. I understand the concepts of special relativity and the lorentz transform, and why it is applied to time, but I can't recall or figure out why Einstein...

There were two threads in short succession in this forum about basic electric circuitry (RC circuit, RL circuit), and it struck me that over the years I've been surprised that the "water circuit" analogy isn't used more than it is. That is, in a system with a circular pipe that contains water...

I have a construction containing two force sensors. http://postimg.org/image/3zv76lo3b/ The sensors are not able to divide the force into components. If a force is applied that ´tips´ the upper plate, I was wondering if it was then possible to divide the force into horizontal and vertical...

Hello, Let ##g_{jk}## be a metric tensor; is it possible for some ##i## that ##g_{ii}=0##, i.e. one or more diagonal elements are equal to zero? What would be the geometrical/ topological meaning of this?

Homework Statement What ques does one need to recognize they need to divide components of two vectors together to "relate the tangents?" The Attempt at a Solution Alright, so I've seen this come up a LOT in the semester-dividing components or sums of components together to work out an equation...

Hello, I'm wondering, is it possible to define an operator on a Hilbert space that gives information about the "distinctness" of superposition components? As a simple example, imagine that we have two particles. Let |3> designate the state in which they are 3 meters apart, let |5> designate...

Homework Statement By considering A x (B x A) resolve vector B into a component parallel to a given vector A and a component perpendicular to a given vector A. Homework Equations a x (b x c) = b (a ⋅ c) - c (a ⋅ b) The Attempt at a Solution I've applied the triple product expansion and...

Let $x \in R - \{0\},$ where $R$ is a domain. Define $T_x(M) = \{m \in M \ | \ x^n m=0 \ \ \mathrm{for \ some} \ n \in \mathbb{N}\}$ as the $x$-torsion of $M.$ I know that $T_x(M \oplus N) = T_x(M) \oplus T_x(N)$ for $R$-modules $M,N$ only if $R$ is a PID. But I can't think of a...

I have always been under the impression that a vector is not "fixed" in space. Given any vector, we could just move it around and it would still have the same components (in a cartesian coordinate system). What confuses me, however, is how we define the components of a vector in polar...

I know that for products produced in the EU and United States, I needn't worry about lead on components. That being said, I many times purchase products from Chinese sellers due to the low bulk price. I recently read that an electrical engineer with the tendency to chew wires while stripping...

The magnitude of the parallel component of the time derivative of a vector ##\vec{A}## is given by: $$|\frac{d\vec{A}_{\parallel}}{dt}| = |\frac{dA}{dt}|$$ Where ##A## is the magnitude of the vector. Can we write the actual derivative in vector form as ##\frac{dA}{dt} \hat{A}##? Notice how I...

Consider a simple textbook problem in two dimensional kinematics - say, a projectile motion problem. I know that the x- and y- components of motion are independent of one another but I don't understand why. I know this is true due to everyday observation - empirical evidence of this being the...

In the book "Introduction to Mechanics" by K&K, an increment of a generic time-varying vector is split into two components, ##\Delta \vec{A} _{\perp}## and ##\Delta \vec{A}_{\parallel}##. Their magnitudes are approximated by: $$A \Delta \theta$$ and $$\Delta A$$ respectively. (Where ##\Delta...

In a combination circuit, with 2 components, if the voltages across each is the same, why must the resistance of the components be equal to each other?

Is the ESD standard different for components(ICs) and systems. For Systems the standard I refer is IEC61000-4-2. For ICs, I am not sure. Does HBM and CDM apply to only components or does it apply to systems too? Is the Automotive ESD testing levels different than the industrial ones( 4KV...

In the way of defining the adjoint representation, \mathrm{ad}_XY=[X,Y], where X,Y are elements of a Lie algebra, how to determine the components of its representation, which equals to the structure constant?