Zero Definition and 1000 Threads

Homework Statement Homework Equations \begin{align} \begin{split} \psi(x, t) = e^{(ikx- i \omega t)} \\ V(x) = 0 \end{split} \end{align} The Attempt at a Solution For a free particle, the Schrödinger equation can be put in the form of ##\psi(x, t) = e^{(ikx- i \omega t)}##...

Homework Statement I am pushing a very heavy ball with full strength, but the ball is not moving at all. So, there is no change in momentum of the ball. Is it appropriate to say that the Force applied to the ball is zero ? Homework EquationsThe Attempt at a Solution

Homework Statement I am trying to solve a problem from a popular quantum mechanics text. I am learning on my own. I am trying to calculate the variance, which is <x^2>-<x>^2 = variance in x. I posted a photo of the problem as a picture that is linked below as well as the solution, I simply...

Hello, I've been trying to answering this question but my answer is always wrong. Two point charges, -9.10 μC and 21.29 μC, are placed at x = 0 cm and x = 8.00 cm, respectively. (a) At what point along the x-axis is the electric field zero? What i did: i figured that the point should be on the...

Hello guys, I'd just like to ask how can I formulate transfer function of second order differential system when I don't have zero initial conditions? the equation is = y''(t) + B/m*y'(t) + k/m*y(t) = g y(0)= -L don't care what parameters mean .. it's supposed to be solved in general Thank...

Look at the following derivation: ## p=\frac{im}{\hbar}[H,r] ## if ##H|\psi\rangle=E|\psi\rangle##, then ## \langle \psi|p|\psi \rangle = \frac{im}{\hbar}\langle \psi|Hr-rH|\psi \rangle = \frac{im}{\hbar}\langle \psi|r|\psi \rangle(E-E)=0 ## What's wrong with my derivation or it is true that...

Homework Statement A tensor t has the following components in a given orthonormal basis of R3 tij(x) = a(x2)xixj + b(x2) \deltaij x2 + c(x2) \epsilonijk xk (1) where the indices i,j,k = 1, 2, 3. We use the Einstein summation convention. We will only consider orthogonal transformations...

This seems a very simple case to me, yet I have heard it said that the answer is some undefined real number. Yet zero times anything means no iterations of whatever the object is; whether that be a real number , an imaginary number or an undefined number. Whatever it is I don't see how one can...

Why do we have the number zero? What makes it important? Can we create math like system that don't use zero but are nonetheless useful. What limits or biases does having or not having zero create when we do science?

Hello everyone, I know that the photon has zero rest mass and I know that otherwise the relativistic mass formula would not make sense. When I searched for an answer to the question "how can a particle have zero mass and still possesses energy if E=mc^2" I got an answer saying the mass energy...

What is the "plane of symmetry", "zero velocity wall" and "free surface" terms which I have seen in Polyflow? It says in Vnormal=Fs=0 for plane of symmetry and Vnormal= Vs= 0 for zero velocity Wall. Now I get when Vs=Vn=0 it means that the wall isn't moving and it's in a static state but didnt...

Homework Statement Question I need help with: If wire AB of problem 9 moves with a velocity of 50.0 m/s to the right, at what rate should B change when the wire is at a distance of 5.00 cm from the left end of the loop, such that there will be no induced emf in the circuit? Answer: 300 T/s...

While balancing rotating mass we consider the inertia force (centrifugal force) is equal and opposite to centripetal force which causes the rotation. if both force(applied external force on rotating mass) which causes the motion and force which resist motion (inertia force) are equal and...

Homework Statement Homework Equations Wronskian theorem: The Attempt at a Solution I've gotten the relationship given by the question but I do not know how to continue. Since ##\psi_n(a)=\psi_n(b)=0##, LHS ##=\psi_n'(b)\,\psi_{n+1}(b)-\psi_n'(a)\,\psi_{n+1}(a)## If LHS ##=0##, RHS...

Homework Statement Okay, I need help quick, exam in few hours, I won't be able to reply to this later. http://puu.sh/lQeXl/42907b0a12.jpg In my lectures notes this is given. In the example shown with it, the one on the right in particular. Look at Joint C, it is unloaded, it also has to...

Gravity does act on a satellite so why is normal force 0 for an object placed inside it?

Homework Statement Solve the following differential equation and compare computer solutions \begin{equation*} 4y''+12y'+9=0 \end{equation*} Homework Equations None The Attempt at a Solution [/B] First of all looking at this equation, even though it is in the section where we learned about...

Homework Statement An ice cube is placed on top of an overturned spherical bowl of radius r, as indicated in the figure. If the ice cube slides downward from rest at the top of the bowl, at what angle θdoes it separate from the bowl? In other words, at what angle does the normal force between...

So since heat comes from atoms vibrating and moving and as they go fast heat increases and when they go slower heat decreases. If I got this right absolute zero is when they give off no heat and this would mean that the atoms are not moving at all. Well then if that is how absolute zero works...

When the shell is grounded(at zero potential), it is essentially empty of any electrical charge. Is it true?I think ,yes.But I think it should be When the shell is grounded, it is essentially empty of any excess electrical charge. Right?

Show that if A and B are square matrices of the same size such that B is an invertible matrix, then A must be a zero matrix.

Let N be any number N÷∞=0 Cross multiplying N=0*∞ Any number multiplied by zero is zero Even infinity is a number but it is large So N = 0

The question is: The voltage source in the above circuit is a sinusoidal AC source with constant amplitude and constant phase shift but an adjustable frequency. Calculate the frequency ω at which the phasor current I...

Hi - from orbital angular momentum components, $[L_x, L_y] = iL_z$ My book claims 'Hence, $ \vec{L} \times \vec{L} = i\vec{L} $' I'm keen to know how they get that, an also why that cross products isn't = 0, like $A \times A$ would be ?

Dear all, The term "big bang singularity" somehow seems to imply that the universe had zero extent at the beginning. But should this really be taken literally? Because if something has literally zero extent, then not even exponential growth over billions of years could ever result in an extent...

If any positive energy always has a negative energy counterpart, then nothing ever exists. Am I missing something here?

I read about a theory according to which the sum of everything the universe is made of is likely to be zero. For example, forces cancel each other, positive and negative energy cancel each other, and so on. Is there some support for this theory, or is it generally dismissed?

Find the point between the sun and the Earth where the gravitational force on an object is equal to zero I know the mass of the sun is 1.989 x 10^30 kg G = 6.67 x 10^-11 The distance between the two is 1.49604618 x 10^11 The mass of the Earth is 5.962 * 10^24 I have the equation F =...

If zero is the additive identity and one is the multiplicative identity, is there an operation for which infinity is the identity?

Homework Statement [/B] Find the instantaneous centers of the linkage below. Homework Equations # of ICs = n(n-1) / 2 The Attempt at a Solution [/B] From the equation above, there are 4(4-1)/2 = 6 ICs in this linkage. But one thing I don't understand is how there are 4 links when 2 and 3...

I understand that a standing wave in one dimension is a superposition of a traveling wave going one way with a traveling wave going the other way. Does that mean that the momentum at every point along the combined standing wave is zero? For example if one has elecromagnetic standing waves...

So my question is simple. If the current doesn't change sign, is it considered AC or DC? I seem to recall we called it DC when I briefly saw it. However after a quick google search I'm confused. Some said that for example an AC signal offset with a DC signal to show this behaviour should be...

1. Homework Statement Homework Equations P=IV, =I2R =V2/R The Attempt at a Solution For zero resistance, I used P=V2/R formula, and sub. R=0 , power would be infinite. But if I sub. Into P=I2R, power will be zero. The correct answer should be zero. But why do we need to use the second...

What happen to gas particles at absolute zero? Is it possible that the particles will still be moving ? Thanks in advance

I've just learned that the conductivity of super conductors increases with decrease in temperature and it becomes infinite at absolute zero. But I thought that all motion ceases at absolute zero. So how can current flow in such conditions? And how can its resistance become zero as some...

Homework Statement In the Principles of Physics book chapter two in checkpoint 2 claims that If velocity of object is zero its a constant velocity.I am confused cause v=0 means there's no motion.Without motion we can't talk about constant velocity.I am confused.(The equation of object is...

I was wondering how members CL and JE are zero members? They both have forces applied to them, so why would it be zero? The attached image is the solution.

All elementary particles, which are not made up by any other particles (electrons, quarks), are said to be zero dimensional and have no size. But why not? Are electrons literally zero dimensional particles with no size?

Homework Statement Looking for the tension in cable Tcd when the moment on A is equal to 0. P1 = 73N. I’ve had several attempts but I can’t seem to obtain the answer, which is 110,8 N. Can anyone help me with this question? Homework EquationsThe Attempt at a Solution

http://imgur.com/lPIRaie 1. What are the Zero force members in this truss? 2. Is the truss internally statically determinate? Im not too sure what question 2 is but I would guess yes? Many thanks~

I just finished writing a computer program that takes as input a number of matrices and computes the inverse of the product of matrices. To test this program, I wanted to input a 3x2 matrix followed by a 2x3 matrix so that the product would be a 3x3 matrix. No matter how hard I try, the...

There are rings such as P_3 in which every element not equal to 0 or 1 is a divisor of zero. Explain why this is not possible in any ring of polynomials A[x], even when A is not an integral domain. I can't see how to answer this. If I define A as Z_3 with the usual addition and define...

Homework Statement Consider the figure below, we need to find the charge on Q_0, both charges Q are negative. It is given that the net charge on Q_A is zero. The figure of the problem is attached. The Attempt at a Solution I understand how to get the solution except for one part. I'm just...

Homework Statement Block m1 has mass 10kg and 10m/s Block m2 has mass 5kg and 0m/s Energy loss is 0%Homework Equations Conservation of momentum Conservation of energy Quadratic Equation The Attempt at a Solution (mv)1i + (mv)2i = (mv)1f + (mv)2f 10(10) + 5(0) = 10(v)1f + 5(v)2f v_{2f} =...

I understand that ψ goes to zero as x goes to infinity. Is it also true that dψ/dx must go to zero as x goes to infinity?

in the video above the instructor explains from time 8:22 to 8:55 that how and why electric field lines going out from the surface which do not enclose charge is zero but I don't understand then why not electric field lines going out from the spherical surface ( enclosing charge) is...

It seems that some of the new "free lunch" cosmological models promote the idea that if the universe has zero net energy, zero energy was required to create it. However, a closed system can have tremendous potential energy but zero net energy, so the idea seems questionable to me, even if the...

Homework Statement A cylindrical shell of radius R and length H has its charge uniformly distributed on its curved surface Find the electric field at a point P from the axis, a distance r away, measured radially outward from the midpoint of the shell such that R>r Homework Equations φ =...

Homework Statement A charge of 2.21E-9 C is placed at the origin, and a charge of 3.78E-9 C is placed at x = 1.60 m. Find the position at which a third charge of 2.94E-9 C can be placed so that the net electrostatic force on it is zero. Homework Equations Coloumb's law The Attempt at a...

Hello, PF! I had a quick question that I hoped maybe some of you could help me answer. The question is simple: Why is the cross product of two parallel vectors equal to the zero vector? I can see this easily mathematically through completing the cross product formula with two parallel...