Components Definition and 911 Threads

I am trying to understand why in a SHM, the acceleration has multiple components(when actually we create such expressions mathematically by approximating the trigonometric expressions using the binomial theorem).I will explain what I mean to ask below with an example. In a internal combustion...

Hi all, I know about Kirchhoff's voltage and current laws when it comes to simple circuits with two-terminal elements and junctions/nodes of branches. However I'm curious how KVL and KCL are applicable to multi-terminal elements? Does KCL apply to any junction of branches no matter what that...

Inspired by a question in Griffiths' E&M book (1.10), I am wondering why the components of a vector do not change when the coordinate system is translated by a constant vector. I understand that, for instance, the velocity of something moving in a coordinate system won't change if we then...

Hello .Sorry for all the questions I am asking...but I have another one I would like to seek help for.: Suppose a system has 10 components and that a particular time the jth component is working with probability 1/j for j= 1,2,...10. How many components do you expect to be working at that...

I just recently built a low-pass butterworth filter with a cutoff of 50Hz. When I looked to purchase the parts, I noticed that each inductor had a resistance of several hundred ohms. I put this information into my simulator program and the result was something that looks nothing like the...

Homework Statement (this is translated from Italian so it might have some technical mistakes :) ) A target with negligible dimensions is placed at H = 5m from the ground; a vehicle on the ground is moving at a velocity V = 2m/s (the module) and is getting closer to the target. Consider O the...

I am not sure if I am allowed to post these kinds of questions here (cause I see mostly hypothetical ones, but then again I didn't look too far down the page...) but I just have a quick question for you guys. I am trying to desolder some electrical components from a board but I don't have...

I've been reading about principal components and residual matrixs. It's my understanding if you used every principal component to recalculate your orginal data, then the residual matrix should be 0. Therefore, I created a fake dataset of two random variables and calculated the principal...

Hello, I would very much like someone to please clarify the following points concerning tensor summation to me. Suppose the components of a tensor Ai j are A1 2 = A2 1 = A (or, in general, Axy = Ayx = A), whereas all the other components are 0. Is this a symmetrical tensor then? How may Ai j be...

Hi all, I would appreciate a little guidance on some circuit theory. I was wondering how a circuit behaves when there are, say two identical 10V cells, and a 1Ω bulb happily sitting in series, but then one connects another identical bulb between the two cells. Obviously the current in the first...

Hi, Homework Statement The components of the tensor Ai j are A1 2 = A2 1 = A, whereas all the other components are zero. I am asked to write A(BAR)i j, following a transformation to a new coordinate system, given that ∂q(BAR)k/∂qn = Rnk. I am expected to write my answer in terms of R...

hello all I want to find costs of some components of a combined cycle power plants.like turbine.generator and ... how can I find them?

Being asked for the sum of forces in the X and Y directions and the axis are set up 'normally' so like a plus sign ( + ). I attempted the first one and I think I did it correctly, but I'm not so sure about the second one.

Hi, I'm interested in building a breadboard version of the simplest comparator using transistors and resistors. Ultimately I'd like to understand the LM393 but looking at the datasheet schematic, it seems quite complicated. I was hoping there was a simpler comparator I could mimic to start out...

The problem is: A 10 kg sled is pulled at an angle of 35 o east of north by a force of 100 N and with a force of 150 N directed due east. A friction force of 50 N acts as well. What is the acceleration (both magnitude and direction of the sled. My question - could someone help me properly...

It's just for educational purpose, not a homework question :) Can you guys please identify all the five components/parts starting from the black socket like thing on the left for me? Thanks in advance!

So, i have been learning about forces, vectors and such. I know many times for convience we break vector forces into rectangular components...fx=Fcostheta, fy=Fcostheta. It is easier to do regular alegbra verus vector alegrba My question is both fx and fy are scalars, but then they can be...

From the book of Nakahara "Geometry, Topology and Physics": A diffeomorfism ##f:\mathcal{M}\to \mathcal{M}## is an isometry if it preserves the metric: ## f^{*}g_{f(p)}=g_{p} ## In components this condition becomes: ## \frac{\partial y^{\alpha}}{\partial x^{\mu}}\frac{\partial...

Hi, I am working through GR by myself and decided to derive the Friedmann equations from the RW metric w. ( +,-,-,-) signature. I succeeded except that I get right value but the opposite sign for each of the Ricci tensor components and the Ricci scalar e.g. For R00 I get +3R../R not -3R../R . I...

In my physics book there is an example of making a square wave by "simply" summing up a few cosine waves. The book says these first three waves are the first three Fourier components of a square wave, yet when I sum the three wave functions up, I get something way off; as does my calculator...

[SIZE="4"]Assume we have a concentration of any specific material (in mg/M). Let's say for example: Ag (Z=47) with concentration 10 mg/M in water (H2O, Z=7.42). How can I calculate the effective atomic number (Zeff.) for the silver-water mixture if the concentration of silver was 10 mg/M for...

I suppose this is less of a "help me with a problem" question than a question asking why something happens. All semester I have been working with vectors and vector components in my general physics class. I understand how to do it and how to solve a complex problem using this method. What I...

I wonder if someone can help me how to find the symmetrical components of a 5-phase system. What would be the positive and negative sequences? I'm saying this because in a 3-phase system I can find the positive, negative and zero sequence in function of line currents.

Homework Statement A simple RC circuit with an EMF source ε, Resistor R and capacitor C are in series. When the switch is closed find the rate of energy stored in the capacitor, the power dissipated in the resistor, and the power supplied by the emf as functions of time. Homework Equations...

Electrodynamical wattmeter has 4 connections, 2 for current and 2 for voltage. Why do we have both, how that works inside? Those 2 drive in current and those 2 voltage so it calculates how much power is it in there in some sort of mechanism? What about in varmeter, why we connect one inductor...

the wiki article on vector meson dominance says "hadronic components of the physical photons". How can a photon have hadronic photon components? Could someone please enlighten me?

Hi guys, Just wondering if there Is a way in multisim to design your own components from scratch? basically starting with the input and output pins and you fill in the gate logic on the inside. Im designing an old school binary-BCD for 12 bits. I've got the theory all figured out, and I...

All, please help me refine, restate, explain, understand, expand, add, remove, answer the below statements/ questions. Thanks in advance. 1.) Voltage is considered a scalar quantity. (J/C in SI Derived Units) which is a magnitude of energy per coulomb...no direction with this example. Some...

I've been tearing some old PCBs up so I can build a nice collection of transistors and caps for myself, but the problem is I haven't figured out how I'm going to pull them off the PCB without cutting the legs off. For some reason the solder is very strong and won't melt. I even took a propane...

I think this may be a simple yes or no question. I am currently reading a book Vector and Tensor Analysis by Borisenko. In it he introduces a reciprocal basis \vec{e_{i}} (where i=1,2,3) for a basis \vec{e^{i}} (where i is an index, not an exponent) that may or may not be orthogonal...

Consider a circular hoop with a radius R and a mass M. Initially the centre of mass of the hoop is spinning, but not moving. Then a object with mass m is thrown at speed v by a spring-loaded gun with an angle of theta anticlockwise from the posive horizontal. Calculate the x and y components of...

Hi I'm a bit confused about what actually define the components of a form. I just saw an argument where one found that \underline{d \omega}^\rho (\vec e_\mu \wedge e_\nu) = - c_{\mu \nu}^\rho and then the author wrote that this implied that \underline{d \omega}^\rho = - \frac{1}2...

Homework Statement I know this is easy, but i can't seem to sort out how to structure it properly. This is the question: A man is pole vaulting. Also ignore air resistance. A man exerts a force of 810 N on a pole, at an angle of 80 degrees below the horizontal. If the man's weight is 600 N...

Hi guys I would like to know, what are the basic mechanical components in modern machines? I am not referring to bolts, fasteners or gears, I'm more asking in a level of differentials in automobiles, power shaft, so on so forth. because I am sure automobiles,aircrafts, missiles...

Homework Statement Hey guys, I have this question. Given a tree T = (V , F), find an algorithm which finds u in V, so in the graph T = (V \ {u} , F) the size of each connected component is |V| / 2 at most. What is the complexity? Homework Equations The Attempt at a Solution...

Homework Statement One end of a cord is fixed and a small 0.500 kg object is attached to the other end, where it swings in a section of a vertical circle of radius 2.00 m as shown. (I don't have access to a camera right now, apologies.) When the angle is 20.0 degrees, the speed of the object...

I'm stuck on the second part of this question. Suppose a particle moves in a plane with its trajectory given by the polar equation $r=2b\sin(\theta)$ for some constant $b>0$. (i) Show that this can be written in Cartesian coordinates as $x^2+(y-b)^2=b^2$. This is the equation for a circle of...

A woman who can row a boat at 6.4 km/h in still water faces a long, straight river with a width of 6.3 km and a current of 3.3 km/h. Let i point directly across the river and j point directly downstream. If she rows in a straight line to a point directly opposite her starting position, (a)...

Homework Statement I'm trying to understand where the Cartesian components of the rotor and the divergence of a vector field derived. I read that the divergence of a vector field is defined by: \vec { \nabla } \cdot \vec { F } =\lim _{ V\rightarrow \left\{ P \right\} }{ \frac { 1 }{ \left| V...

Homework Statement http://imageshack.us/a/img5/629/meprob25.jpg A. Determine magnitude of resultant force (of F1 and F2 acting on the point) B. Resolve F1 into components along the u and V axes and determine the magnitudes of these components. C. Resolve F1 into components along the u...

If I have a periodic function that is say a sum of a number of sine functions I can use a Fourier Transform to get the component functions. Now, if I have a bunch of square waves of differing amplitudes and frequencies that I add up into a resultant waveform. Given that waveform what'd be...

Homework Statement What is the magnitude of the velocity at t=4.00s? I would like to see if my approach and answer is correct. Homework Equations Position: r = {-30cos(\frac{\pi}{10}t) i + 30sin(\frac{\pi}{10}t) j - (7t) k} ft The Attempt at a Solution I took the first...

Homework Statement http://i.imgur.com/B1hFY6E.png Homework Equations -Basic geometry -Similar triangles (?) -Pythagorean Theorem The Attempt at a Solution -I need to find the angle the bar AB makes with the horizontal, correct? And with that, I will be able to figure out the...

The part of the tire on the ground of a moving car is relatively stationary compared to the ground, right? The way the wheels work is the friction parallel to the direction of movement right? So when we calculate centripetal acceleration for cars going in a circle and the friction forces, why do...

Homework Statement Consider a closed semi-circular loop lying in the xy plane carrying a current I in the counterclockwise direction, as shown in Figure attached. A uniform magnetic field pointing in the +y direction is applied. Find the magnetic force acting on the straight segment...

Homework Statement My textbook shows a vector B 130° from the positive x-axis. B has a value of 5; it asks for the x and y components for B. But they show a way other than SOH CAH TOA. They got the x component by multiplying 5(cos130°) and the y component by multiplying 5(sin130°). What...

Why does the incomplete gamma function have an imaginary component, when the exponential integral does not? \Gamma(0,z,\infty)\equiv\int^\infty_z \frac{e^{-t}}t dt Ei(z)\equiv-\int^\infty_{-z} \frac{e^{-t}}t dt Looking at how these integrals are usually defined I would have expected them to...

I want to find [M_i, M_j] Poisson brackets. $$[M_i, M_j]=\sum_l (\frac{\partial M_i}{\partial q_l}\frac{\partial M_j}{\partial p_l}-\frac{\partial M_i}{\partial p_l}\frac{\partial M_j}{\partial q_l})$$ I know that: $$M_i=\epsilon _{ijk} q_j p_k$$ $$M_j=\epsilon _{jnm} q_n p_m$$ and so...

I have questions regarding the physical interpretation of Dirac 4-spinors. Using the Weyl/Chiral representation and the electron as the particle, in the rest frame of the electron, the 4-spinor reduces to two identical 2-spinors, that is to say the 4-spinor takes on the form (a b a b)...

Homework Statement A parallel system functions whenever at least one of its components works. Consider a parallel system of ##n## components, and suppose that each component works independently with prob 1/2. FInd the conditional prob that component 1 works given that the system is...