Stability Definition and 478 Threads

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...

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

Hello, I'm an Electrical engineering student taking a class on surface chemistry. I've been given a problem where I need to analyse the stability of droplets using Unduloids. I have some lecture notes on unduloids in the context of this subject and it's quite limited, but every other...

Homework Statement A steel girder with a mass of 1000kg and a length of 10m rests on a concrete slab, with 4m overhanging the edge. How far can a 100kg man walk on the girder? The Attempt at a Solution I supposed that the right end of the slab is the fulcrum (rotating point), and...

how is aspect ratio of a wing related to longitudinal static stability (LSS)? like, if we increase the aspect ratio, is it going to increase or decrease the longitudinal static stability (LSS)? suppose we have an aircraft whose centre of gravity is fixed at a particular location, if the...

Just for the record: http://newscenter.lbl.gov/press-releases/2009/09/24/114-confirmed/ Cal Pride! :biggrin: Does anyone want to explain specifically how or why there is an island of stability?

Homework Statement In natural water containing 0.9 mmol/L calcium and 12 ug/L fulvic acid, determine the fraction of the fulvic acid that is bound to calcium (i.e. the ratio between the concentration of Ca-FA and total concentration of FA binding sites), assuming that calcium is the only metal...

I am trying to analyze the stability of a particular component of a non-linear differential equation system. It is a dynamical equation and the criterion for instability of a particular axis will help me determine whether there's a drastic switching event in the solution. My solution is a time...

Homework Statement You go to a quick – fix garage to get your brakes worked on. When your tires are re – installed, the mechanic forgets to put the lug nuts on your tires. Although nobody gets hurt, a tire comes off your car when you are traveling fairly rapidly and it is able to roll...

I was reading this on wiki: http://en.wikipedia.org/wiki/Lagrangian_point In the stability section, it claimed that for L4 and L5 to be stable the following must hold: \frac{M_1}{M_2}\geq24.96 Why is this the case? Where can I find proof?

"The rather strong acidity of trichloroacetic acid is usually ascribed to the inductive effect of the three chlorine atoms attached to the end of the molecle opposite the acidic proton. Electron density is withdrawn away from the carboxylate group so that the trichloroacetate anion that is...

A hydrogen atom is consists of a proton (uud quarks) and an electron. Is there a heavier atom of hydrogen that consists of a type of proton (ccs or ttb quarks) and a muon or tauon respectively? Are these

A considerable portion of E. Antarctica ice (average of 1.6 km height) rests on bedrock of 2000+ ft above sea level. https://www.physicsforums.com/showthread.php?t=344123" Would such a core suffice to cover enough glacial and inter-glacial periods; giving an adequate sample? Would any evidence...

If "unzipped" PNA and DNA combine to form a double helix, will the hybrid be more or less stable than a pure DNA double helix? This was a question on my chem homework (in a section on intermolecular forces), but I'm posting in this section as I already turned in the homework so I'm asking more...

I've just learned by chance about http://en.wikipedia.org/wiki/Earnshaw_theorem which states that point charges cannot be maintained in a stable stationary equilibrium. But then, what does the negative electric potential energy (in this thread ...

Alright, there's something I don't understand. The book says that the gain margin and phase margin must be non-negative for a minimum phase system to be stable. But the definition of a minimum phase system is one without right half plane poles or zeroes. Doesn't that inherently make it stable...

Neutrons bind Protons in nuclei, and/or the other way around, but why don't Neutrons bind Neutrons, with clumps of neutrons whizzing about? And, I'm guessing this is related: Why is a Neutron unstable outside its nucleus with about a 10.3 minute half-life?

Why does in QM the electron does not fall toward the nucleus? After all, the only force between nucleus and electron is attractive. It seems that the electron can and does indeed fall toward the center in <simple harmonic oscillator>? My question is what's so different in these two systems...

I have a question related to that is explained on the textbook Sedra & Smith. for a pole at s=a+bj,say, 1/(s-a-bj) why can we have the time domain of the signal to be exp(at+jbt)? It is strange because s=jw, so Re(s)=0 <a ,which leads to the solution to be -exp(-at-bjt)u(-t), so that...

Homework Statement Nitrogen trifluoride, NF3, is relatively stable toward decomposition to its elements. In contrast, NCl3 can be dangerous to work with because of its tendency to decompose to N2 + Cl2, Use bond energies to rationalize. Homework Equations Bond energies for N-F is 278...

I want a MATLAB code to draw the root locus for a characteristic equation of a transfer function of unity feedback, also what is the range of K that keeps the system stable , here is the characteristic equation: s^5+600s^4+50000s^3+ks^2+24ks+80k=0 please help, thanks in previous

Homework Statement This is the autonomous differential equation: x" - 2x' + 37x = 0 Solve the above DEQ and state whether the critical point (0,0) is stable, unstable, or semi-stable. Homework Equations Solution to the above DEQ is x = c1excos6x + c2exsin6x The Attempt at a...

Hi! I'm a maths student taking a maths by computer course and this week's homework deals with the kapitsa pendulum (reversed pendulum). Homework Statement Kapitsa Pendulum is a rigid-rod pendulum the suspension point of which is vibrated. It turns out that vibration can stabilize the...

The recently announced $275B http://www.whitehouse.gov/blog/09/02/18/9-million-plus/#TB_inline?height=220&width=370&inlineId=tb_external" states that it intends only to reach 'millions of responsible home owners'. Indeed, Press Sec. Gibbs said today that the bailout is for ''those who have...

Homework Statement Hi all. I am given by following linear system: \begin{array}{l} \dot x = dx/dt = ax \\ \dot y = dy/dt = - y \\ \end{array} The eigenvalue of the matrix of this system determines the stability of the fixpoint (0,0): A=\left( {\begin{array}{*{20}c} a & 0 \\...

The problem and my work is below...I believe I got the problem to work out. The only question I had was if I found the LEAST moment of inertia which is what's needed for the formula at the end of my calculations. What exactly is meant by the least moment of inertia...

Im working on a problem involving a 70 lb empty drum. The diameter and length are given. I am trying to find if it will float stably if placed upright in water. I did a similar problem to this involving a solid cylinder with no problem. But I am trying to figure what special...

Hi, I am a student pursuing an MS in Aerospace Engineering with a concentration in Aerospace Structures. I am currently taking a course in Stability of Structures. The "required" textbook is Guide to Stability Design Criteria for Metal Structures (ISBN 0471127426), and the other recommended text...

I have a system transfer function H(s) = 1/(e^s + 10) This system has both poles and zeros at infinity and -infinity. Can anybody tell me if this is a stable system. Thanks.

Hello! Quick question, but it's really bugging me! Exergonic reactions often yield polar molecules as the products (e.g. combustion of methane). Are these polar molecules 'favourable' because the electrons are spending more time in a lower energy region; or is this wrong, and there's a...

I know some fine-tuning conditions which must be true in order for our universe, as we know it, to exist, for stars to shine and for the life to develop. For example, * CP violation (otherwise no matter because everything would annihilate) * Diproton (p+p) must be unstable (otherwise stars...

Does H2O2 stay stable once diluted in Water kept at 5-10 degrees. If so for how long?

Which one of these alkyl halides forms the most stable carbocation in a E1 reaction? Not II because it has an even number of delocalized electron pairs. Isn't I, IV and V the same?

Homework Statement How can i classify (1) stable node (2) saddle and (3) center as either (a) stable or asymptotically stable? Homework Equations <None> The Attempt at a Solution All three are stable. Stable node seems to be asymptotically stable. But I am not...

Homework Statement You are riding in a train and have just opened a bottle of beer. Prove that for your bottle to be as stable as possible on the table (which is shaking), you should drink sufficient beer such that the surface of the beer coincides with the centre of gravity of the...

1) As far as i think i understand, stability of a polynomial means; the polynomial correspond to a (its inverse laplace transform) differential equation, and the differential equations solution is dependant on the coefficiants of this polynomial? if the polynomial is unstable the solution of...

Hi, I have a choice of taking this advanced ODE course, and I am wondering if this is worth studying. The course will cover mainly chapter 9 of Boyce/DiPrima textbook after we cover existence and uniqueness theorem. Chapter 9 is called "Nonlinear Differential Equations", and covers topics...