Stability Definition and 525 Threads

Homework Statement I want to know if i got answer to C correct http://img822.imageshack.us/img822/7804/equilbrium.gif Homework Equations The Attempt at a Solution [PLAIN][PLAIN]http://img703.imageshack.us/img703/508/equilbriumsol.gif

I have the impression that when discussing stability of nuclides that there are two different usages of the term. 1. Atomic weight divided by nucleon count: The lower the number, the more stable is the nuclide. Iron ending up being the most stable. 2. Radioactivity: All nuclides that...

Hi, Could someone clarify the following statement please? "ZnO has a bandgap of 3.4 eV at room temperature and a free exciton binding energy of 60meV which is much larger than the room temperature thermal excitation energy (25meV) making them stable at rtp." Does it mean that at rtp, we...

Hi Everyone, I have been researching for days, and am still very confused, so thought I might turn here for assistance. I know the minimum free energy represents the state of maximum stability for a system. Free energy is decreased when enthalpy decreases and entropy increases. I understand...

Homework Statement I have two questions. I have attached two pictures, 1 for each. 1. For the question about stability, the answer is C, but I thought it should be B. I would imagine the strain of two OH groups would be greater than an OH group with a CH3 group. Can someone explain what...

Hello Guys, I am planning to design electrical grid connected with solar distribution generation system using ETAP. I tried to run trasinet stability analysis of this system with fault at each and every line/branch of the system, to get corresponding critical clearing times. I realized that...

Just totally confused which value to use to get the area moments of inertia with this question The ship was initially looks like this the mass of the ship is 5000 tonnes two heavy cargocontainers each of mass 73,370 Kg each assume that the ship has a rectangular waterline area, with length...

Homework Statement C3H6 cyclopropane C4H8 cyclobutane C6H12 cyclohexane Looking at their bond angles, which do you think is most stable? The Attempt at a Solution I'm trying to examine their shapes - triangle, sqaure and hexagon, but I don't know which shape is more stable...

Stability and Critical points---Please Help Homework Statement I need to know the critical points and stability of this ode (2xy-5)dx+(x^2+y^2)dy=0 Homework Equations The Attempt at a Solution i've graphed this is Mathematica (attached) but I don't know if its stable or what the...

Homework Statement An object is restricted to movement in 1-D. Its position is specified along the x-axis. The potential energy of the object as a function of its position is given by U(x)= a(x4 − 2b2x2), where a and b represent positive numbers. Determine the location(s) of any equilibrium...

Homework Statement [PLAIN]http://img825.imageshack.us/img825/2673/58894277.png Homework Equations sin(theta) ~ theta for small angles. The Attempt at a Solution I'm having a hard time understanding what the question is asking since I don't have a lot of experience in stability...

Hi - I'm designing a dining table, and am trying to calculate how much weight could be applied at the edge of the table (if someone were to lean or sit on it) before it would tip. If the legs are set in about one quarter of the total width of the top, can the outer edge of the table carry a...

Hi everyone, I was looking for a std to calculate stability of truck mounted crane. Recently I found an australian std "australian code of practice for crane installation on truck" (I think it is a part of 1418 au std), and I found it simple and practical. But, when I tried to solve the example...

I have the following DE: y'=y*(1-y^2) And understand that y=0, and y=+/-1 are critical points I am confused as to which are stable/unstable and why. TIA

i was just thinking...considering the Earth as a system would we consider the Earth as a stable system?if so can we prove by contradition that it is not unstable...and more so what parameters would we consider in forming the differential equation..its just crazy thinking.. hope i have posted...

why doesn't nitrous oxide decompose to nitrogen and oxygen at rtp even though the gibbs free energy is -105 ? thanks!

Homework Statement Classify the fixed points of the following linear system and state whether they are stable or unstable \dot{x}=x + y \dot{y} = x + 3y Homework Equations The Attempt at a Solution Fixed point at dy/dx = 0/0. Therefore fixed point = (0,0) How does one test...

Homework Statement Why is it important in brachytherapy to realize that rhodium is not a stable isotope? If rhodium were not a stable isotope, what considerations must one make? I know that a stable isotope can go from one element to another, but I don't see how that would have anything to...

Homework Statement A uniform plank of thickness 2d and weight W is balanced horizontally across the top of a circular cylinder of radius r, whose axis is horizontal and perpendicular to the length of the plank. Prove that the gain of potential energy when the plank is turned without slipping...

I am reading the beginning of the chapter about Conjugated Unsaturated Systems and it is discussing relative stability of the allylic radical in comparison with other compounds. This is what it tells me for the DH°: Allylic Radical - 369 kJ*mol-1 3° Radical - 400 kJ*mol-1 2° Radical - 413...

My teacher explained that when a large nucleus has too few neutrons, the binding energy is not enough to hold the nucleus together. But by adding neutrons the binding energy increases without increasing the repulsion between nucleons, and thus the nucleus can stay together. But atoms that have...

I've read (in wikipedia, at least) that neutron-degenerate matter is unstable in small quantities, and would decay into protons, electrons and antineutrinos. Is there any generally accepted estimate for the critical mass at which a ball of neutronium would be stable? (Trying to calculate...

analysis of circuits towards stability ... I studied so many materials and some of those are describing about analogue corcuits for many purposes. In part of that everytime they explaine about pole ZERO concepts(whenever i seen those words in paragraph i feel that is bad ). I need to overcome...

Hello. I have a question concerning the stability of a hypothetical binary planet system. I'm sorry if this properly belongs in general astronomy instead of astrophysics, but it does concern orbital mechanics. The hypothetical system is an Earthlike planet orbiting a relatively bright K class...

My friend asked me that this morning but I couldn't think of the answer. I know there's probably some major physical law behind it, but so many to choose from! Can you guys help me clarify this issue for myself and my friend?(when I say "riding a bike" - I mean riding on a bike. When I say...

After analyzing a 3-DOF system, I've obtained the following 6th order characteristic polynomial: P=\lambda^6+(6\beta-.8896)\lambda^5+(8\beta^2-3.5584\beta+6)\lambda^4+(\beta^3-.8896\beta^2+16\beta-3.5584)\lambda^3+(3\beta^2-1.7792\beta+8)\lambda^2+(3\beta-.8896)\lambda+1 Stability is...

Hi I'm looking for a good description (high-school to 1st year level) why the ratio of protons to neutrons matters for stability. Single neutrons are unstable, but in a nucleus they are stable and the more nucleons you have the greater the strong force. So why can't you have stable isotopes...

Homework Statement Consider a discrete-time system, driven by: x[k+1] = Ax[k] for non-zero inital conditions x[0] a) write the closed-form solution of x[k]. If the system is asymptotically stable how should x(k) behave? b) what is condition for asymptotic stability? Homework Equations...

hi, does anyone there know why two (antiparallel) electrons with net spin 0(paired electrons) are more stable than two unpaired electrons? is it because the magnetic attraction between the magnetic dipoles of these 2 electrons? this is a basic question therefore I need to understand it...

Case in example: If a motorbike is being riden down a steep hill and out of gear with no brakes applied; would this be more unstable than if the bike were in-gear using engine braking? (Above condition being at the same speeds).

Consider the following system (where B is a real number, B is not equal to 0), x1' = -2x1 + (B+2)x2 x2' = Bx2 Depending on the value of B, the critical point at (0,0) can be of different type and/or stability. Describe the possible type/stability of the critical point for the different...

hi, i believe there is a clear cut relationship between the pauli exclusion principle and the thermodynamical/chemical stability in chemistry. the pauli principle rises the energy level, and stability occurs for the lowest energy states. does that mean that a consequence of the pauli...

Hello, I'm solving a problem in optics, and I found the next question: Let f:\mathbb{R}^2\rightarrow\mathbb{R} be a function, such as (x,y)\rightarrow(z), which is a surface in IR^3.I need an estimator of the stability of that surface or any indicator of the inclination of the surface in a...

Given these two helicopter designs, which, if any, of them would be more stable? (No image? 1 is propellers on top, body below, second is body above, propellers below) Common sense tells that 1 would be more stable, but experience and rocket pendulum falacity shows that both are equally...

I was bored at work and started spinning m&m's, specifically peanut butter m&m's. If I spin the candy about its minor axis it will rotate about said axis until it reaches a certain velocity and then will rotate and start spinning about its major axis and then as it slows it will rotate back...

Homework Statement Attached Homework Equations 5.104 mentioned in the problem is Also attached The Attempt at a Solution Suppose the mass is moved to (x,y), the distance from the mass to the left spring is denoted by A, the distance from the mass to the right spring is denoted...

We learn in solid state physics that crystals cannot exist in one or two dimensions. The main enemy of low-dimensional crystals is the acoustic phonon (Goldstone mode). Due to its small energy in the long wavelength limit, it contributes signifiantly to the fluctuation of the atomic position...

Homework Statement I'm a little confused as to which conformation of protein is more stable (folded or unfolded)...like in my book it says that the most stable (lowest free energy) is the one with the maximum number of weak interactions...so in this case, shouldn't it be the folded one? but on...

So I just had a question on a quiz (did not go well) about carbocation stability on the fused rings bicyclo[2.2.1]heptane, with the positive charge on a bridgehead carbon and 2-methylbicyclo[2.2.1]heptane with the positive charge on C2. The question was which is more stable and why? The...

Rank the following base pairs according to their stability. Rank from most to least stable. To rank items as equivalent, overlap them. ------------- I have found out that the first one is thymine-adenine pair and the second one is a cytosine-guanine pair. The third one is cytosine...

Hi, I am curious about how to describe the stability of a graph using some form of bona fide statistical analysis. I unfortunately have very little statistical background. The data come from a Computer Science research project I am working on. We are attempting to use simulated...

Hi there! If I want to find the eigenstates of the hydrogen atom in QM I start with the hamiltonian of a free particle in a Coulomb potential. But an electron in a coulomb potential is stable in classical mechanics too! The instability of the system comes from the fact that the electron...

what is quantum chaos? dose it exist realy? the original definition of classical chaos is a system with exponential sensitivity to initial conditions. however in quantum mechanics because of the linear property of the schrodinger equation, variation on initial condition of the wave function...

We consider two stars which initially were at rest with each other, and were gravitationally influencing each other. We assume a kind of gravitation force which propagates at light speed. Now we give equal velocity (in relatively opposite direction) to both stars. Since gravity is propagated at...

In Six Easy Pieces: Fundamentals of Physics by Feynman, the claim is made that the reason why electrons don't just collide “ontop” of the nucleus is due to the Heisenberg uncertainty principle. This perplexes me greatly; it sounds wrong to me. The moon and the Earth do not collide because...

For an RC aircraft which i am working on i was thinking about having static stability at the extreme limits of pitching to prevent stalling and further instability, but i was wondering what to have between the limits neutral static stability or static instability. Static instability may help the...

So, I'm studying Dynamical Systems from Hirsch and Smale's "Differential Equations, Dynamical Systems, and Linear Algebra." For those who are acquainted with the book, the book is filled with typos. However, otherwise, it's great. I obtained this book from my University library and it appeared...

Hi. Im designing an ROV and need to know it will be stabile during "flight". I am considering the (imaginary) line between the center of flotation, CF, and center of mass, CM, as a pendulum. Where the tourqe around CF = -mgl*sin(theta). Theta being the angle between the pendulum and the...

This isn't exactly coursework, since I am no longer in school, but I think this may be the most appropriate forum to post in. This link is for a TI/Unitrode app note, "Control Loop Cookbook", which is about control loops for switching converters...

I am curious to know if there have been any experiments to measure change in nuclear disintegration rates/ gamma emissions with change of distance between quarks in nucleons? Thank you. Douglas