Zero Definition and 1000 Threads

I found this scheme of a zero point switching in a notebook http://img402.imageshack.us/img402/1313/schemew.jpg I'm a bit confused. Look at the SCR on the right with the wide-arching gate... is it really possible to connect an SCR gate like that?

I'm confused about what polarization of a dielectric does to its electrical properties. It is clear to me that polarization causes every little atom to get a tiny dipole moment. A measure of the polarization is therefore P = dipole moment per unit volume. However, what is really a dipole moment...

According to de-broglie's equation λ=h/p, so a/c to this equation what would be wavelength of particle at zero speed?

Homework Statement I've heard this affirmation in an gravitation lecture. I thought it was interesting and decided to check it out. It turns out to be true so I decided to prove it. I'm not a mathematician so proving stuff is not my department. Still I try to do some proofs just for fun. I...

Homework Statement Hi everyone, I'm just wondering if someone could please clarify for me what infinity to the power of zero is? I seem to be finding conflicting opinions about this online. Is it '1' or 'not defined'? Thanks! Homework Equations The Attempt at a Solution

Point charges q1 and q2 lie on the x-axis at points x = -a and x = +a, respectively. (a) How must q1 and q2 be related for the net electrostatic force on point charge +Q, placed at x = +a=2, to be zero? (b) Repeat (a) but with point charge +Q now placed at x = +3a=2. Can someone help me...

Consider a linear operator τ:V→V (where V is finite-dimensional) such that rk τ2=rk τ. Show that (im τ) \cap (ker τ) is the zero space. Here's where I am: Its easy to see that I am τ=im τ2, since it is a subspace with the same dimension. I also know that if (im τ) \cap (ker τ) contains a...

Motion -- zero velocity but still having acceleration What would be a example of a body having zero velocity but still having acceleration, except the example of a body projected vertically upwards and at the highest point it has no velocity but an acceleration equals 'g'?

Hello, I have a simple cosine f = 50Hz. When I generate Matlab code to produce 1/2 second of this signal and take the FFT, the response correctly shows a spike at 50 Hz. However, when I bracket the signal with 1/2 seconds of zeros on either side, the frequency response is showing a spike at...

Hello, I'm sorry if I'm posting in the wrong place. As you can see this is my first post and there's something that's been irking me so much that I need clarification. I'm sure some people will be disgusted at some of the logic, but I just want clarification. I do realize that it's all...

The harmonic oscillator and the rigid rotator are traditional examples in any quantum mechanics text. The former can represent the vibrations of a diatomic molecule while the latter can represent its rotation. By solving the time-independent Schroedinger equation for the two systems, one...

Ok this is from a tutorial I am redoing again. V5 = {(x, 1) | x ∈ R}, (x1, 1) ⊕ (x2, 1) := (x1 + x2, 1), c.(x, 1) := (cx, 1). I understand that there exists a zero vector in this vector space, that comes in the form of (0,1). What I do not understand is why that is considered a zero...

Homework Statement draw equipotential lines and electric field lines for the following arrangements of charges: a) +4 at (3,5) b) +4 at (3,5) and +4 at (6,5) c) +4 at (3,5) and -4 at (6,5) d) +5 at (3,5) and -2 at (6,5) e) +4 at (3,4), (7,4), and (7,7) f) +4 at (3,4) and (7,4) and -4 at...

I have heard people talk about the principle that the total energy of the Universe is zero. Here is my understanding of the principle. The positive rest mass energy of each particle is balanced by the negative gravitational potential energy between it and every other particle in the...

I am examining various models of eternal inflation and I want to double check one of my assumptions, which is that space always expands when the space has vacuum energy and zero mass. Is this correct? Will space always expand when the space has vacuum energy and zero mass? Thank you.

Homework Statement In a current-carrying wire, the total net charge in the metal is zero. Why does the wire experience a force when placed in a magnetic field? Homework Equations The Attempt at a Solution The reason for the force is the motion of the electrons, not their...

The question is: ∫ (y(4-x^2-y^2)^(3/2) dy with y=(-sqrt(4-x^2)) to sqrt(4-x^2)) dy I evaluated it online and it came out to be zero which was quite astonishing since both limits of y are not the same. The limits are the additive inverses of each other. Does this mean that regardless of the...

I know that net torque is the sum of torques in a given situation. So take this as an example: If I used a wrench to turn a nut counterclockwise and it succesfully moves, is the net torque going to be non-zero? If so, then can someone please give me an example where the net torque can be zero...

Homework Statement Assume that a,b,c are all positive constants. Show that all the solutions of: ay'' + by' + cy = 0 tend to zero as x goes to infinity. (I presume that y is implicitly assumed to be a function of x) The Attempt at a Solution This is what I have to far: We write...

Homework Statement The function g:ℝ→ℝ defined by "g(x) = 0 for x being rational and g(x) = 1 for x being irrational" does not have a limit at zero. Homework Equations I have to use the definition of the limit of a function at a point--I can't use the sequential criterion this time. So...

Homework Statement When is the magnetic flux on a section of a closed surface equal to zero? A. When the magnetic field is in the direction opposite that of the section’s area vector. B. When the magnetic field is in the direction of the section’s area vector. C. When the magnetic field...

Homework Statement Let \sigma (E)=\{(x,y):x-y\in E\} for any E\subseteq\mathbb{R}. If E has measure zero, then \sigma (E) has measure zero. The Attempt at a Solution I'm trying to show that if \sigma (E) is not of measure zero, then there exists a point in E such that \sigma (\{e\}) that has...

Homework Statement Is T(X,Y)->(X,Y,1) a linear transformation? where X and Y are defined R2 column vectors. Homework Equations Attempt to prove T(cX+Y)=cT(X)+T(Y) Consider T(cx1+y1,cx2+y2)->(cx1+y1,cx2+y2,1) The Attempt at a Solution RS=cT(x1,y1)+T(x2,y2)->c(x1,y1,1)+(x2,y2,1)...

Homework Statement Homework Equations The Attempt at a Solution It's not so much a homework problem as it is something I was wondering. Our book is horrible, and does not explicitly state that the zero vector is always in the span of two vectors. If I am understanding things right: if v...

Homework Statement If P(x) is a polynomial with real coefficients, then if z is a complex zero of P(x), then the complex conjugate \bar{z} is also a zero of P(x). Homework Equations Book provides a hint: assume that z is a zero for P(x)=a_{n}x^{n}+a_{n-1}x^{n-1}+...+a_{1}x+a_{0} and...

I read in a physics textbook that it is not zero gravity in ISS but the fact that the ISS is in "free fall" makes astronauts float around. They do not feel any normal force because the vehicle they are in are also in free fall along with them. Then I watched Neil Degrasse Tyson talk about bone...

I have a Plot using Frame, and AxesOrigin set to a convenient value. The plot process offsets the physical origin of the Frame so that the specified AxesOrigin is just inside the Frame border - ie there is an offset introduced for both axes. Is there a way to tell Mathematica not to set any...

see this http://www.zeroshortfilm.com/

Hi, I am taking a high school physics course and I just need a little help grasping the concept of zero work and whether or not it applies to this situation... The question reads: A child on a sled (having a combined mass of 47.0kg) is pulled by a force directed along a rope that make a 45°...

Homework Statement Consider two parallel conducting wires along the direction of the z axis as shown below. Wire 1 crosses the x-axis at x = -2.60 cm and carries a current of 2.00 A out of the xy-plane of the page. Wire 2 (right) crosses the x-axis at x = 2.60 cm and carries a current of...

Entropy is defined by: S(A)=\int^{T_A}_0C_V\frac{dT}{T} where A is state of the system in which temperature is T_A. When T_A\rightarrow 0 and C_V must go to zero. Why? And how fast does it go?

Homework Statement The electric field is zero within the conductor because the charges are all at rest in an electrostatic situation. But the electric field inside a cavity within the conductor is not necessarily zero because it isn't part of the conductor, as my book says. Then i encountered...

How I am currently imagining it: In a simple circuit with just a battery and resistor the voltage of the battery sets the electrons off through the circuit at some speed and that speed is proportional to the voltage. The electrons then encounter the resistor. From these forums my...

I have the following exercise: Let s_n be a cauchy sequence in Q(rationals) not converging to 0. Show that there exists an e(epsilon) >0 and a natural number N such that either for all n>N, s_n > e or for all n>N, -s_n >e. I know that since Q is not complete, we cannot assume that there...

How do you prove that there does not exist numbers a,b\in\mathbb{Q} such that 0 = a + b\sqrt[3]{2} + \sqrt[3]{2}^2

change in internal energy is a function of temperature. So if there is no change in temperature then there should no change in internal energy. But consider this example. work done in process work done(W)= nRT*ln(P1/P2) (Δ)T=0; so it's isothermal) heat supplied(Q)=0 (No heat is supplied...

Ok let a and b be non zero numbers (\frac{a}{b}) / (\frac{1}{0})=0 But shouldn't that be undefined since you would get a fraction like this \frac{1}{0} which isn't allowed. Since it got us to a "wrong" answer, that would mean our assumption was wrong. Please tell me where I went wrong.Not...

Homework Statement Im having difficulties with this on several problems. I understand work to be zero when there is either no displacement, no forces acting parallel to object or if friction and air resistance is not considered. Here is a simpler problem where i get the right answer if i...

field inside conductor-is it zero every where?? consider a perfectly spherical neutral conductor.suppose a few electrons with net charge q is deposited on it.the electrons will spread out[due to mutual repulsion] and distribute themselves in such a way that the net field inside the sphere is...

Epsilon-Delta proof of zero?? Homework Statement Write an epsilon delta proof for the limx\rightarrow2 0 = 0. The Attempt at a Solution This is for my discrete math class. I know how to do limit proofs with a variable, like x or x2, but it seems that this is obvious that the limit...

Ok I can do the integral and see that it is equal to 2∏i, but thinking about it in terms of 'adding up' all the points along the curve I feel like every every point gets canceled out by its antipode, e.g. 1/i and -1/i.

I'm struggling here so please excuse if I'm writing nonsense. I'm trying to understand how, for a gravitational field, Laplace's equation (I think that's the right name) equals zero in empty space. I understand that the gravitational potential field, a scalar field, is given by...

This is why I think this is the case, I can't come up with any other reason and have been researching all over the place. I do have a knowledge of circuits, I'm doing an electronic engineering course, but the reasoning has never been explained, as if it's unnecessary to understand why, but I am...

gibbs free energy change at constant pressure is zero?? IS gibbs free energy change at constant pressure zero? ΔS = q / T. At constant pressure q = ΔH so ΔS = ΔH / T So ΔG = ΔH - ΔH/T . T = 0 I think i am wrong but where? My friend tells me that q involved in enetropy is...

Homework Statement A 13.0nC charge is at x = 0cm and a -1.1nC charge is at 6cm. At what point or points on the x-axis is the electric potential zero? Let X0 be a position on the x-axis Let V1 be the electrical potential at a point due to the 13nC charge Let V2 be the electrical potential...

I read about 1/f noise. It says it is inversely proportional to frequency. What would happen at zero frequency or dc? Will it go to infinity? But when we measure some dc value we don't find any infinite voltage which clearly disproves this equation. What is the reason behind this? Thanks in...

I'm looking at a Linear Algebra book that is using the greek letter θ for the zero vector. And the book has other bold letters, so it can't be that they simply could not make a bold zero. Has anyone seen such a usage before?

Hi all, I would just like to get some clarity on units and zero-divisors in rings of polynomials. If I take a ring of Integers, Z4, (integers modulo 4) then I believe the units are 1 & 3. And the zero-divisor is 2. Units 1*1 = 1 3*3 = 9 = 1 Zero divisor 2*2 = 4 = 0 Now, If I...

/// The probability density does not go to zero at the nodes if relativistic effects are taken into account. /// src=wikipedia, particle in a box. /// so does it mean energy levels/atomic orbitals are not necessarily discrete and that atom has to be remodeled. ***pardon my ignorance if I...

Homework Statement A solid insulating sphere of radius a = 5.6 cm is fixed at the origin of a co-ordinate system as shown. The sphere is uniformly charged with a charge density ρ = -159 μC/m3. Concentric with the sphere is an uncharged spherical conducting shell of inner radius b = 10.7 cm, and...