Constants Definition and 458 Threads

Hi, I am currently attempting to implement the Gillespie algorithm for an artificial gene network. I have been given a set reactions and their accompanying equilibrium constants. However, to execute the algorithm I must know the rate constant of the reaction (units of 1/s). I know that the...

Are there any books, written for the layman, which talk about observable effects that might be caused by our 5 (4 + time) dimensional portion of the universe moving through the larger universe. "Universe in a Nutshell" -Hawking, talks about how gravity may transend branes. Are there others?

Homework Statement This is an example from a book. I am having trouble in substituting the numbers to get the given result. Homework Equations The bar notation is to indicate the operating point. The subscript A is for the reactant A (which reacts and becomes product B in a A->B...

Homework Statement Let A be the area of the region in the first quadrant under the graph of y = cos (x) and above the line y = k for 0 <= k <= 1. a.) Determine A in terms of k. b) Determine the value of A when k = 1/2. c) If the line y = k is moving upward at the rate of ( 1 / pi )...

Homework Statement A toy car with mass 0.02 kg is propelled by a spring with a spring constant 80 N/m onto a track. The track. The track contains a loop of radius 0.10m. Ignore any losses dueto friction and use g=10m/s. What is the minimum compression of the spring necessary for the car...

I have an equation I am solving with Mathematica: In: DSolve[y''[t] + Subscript[\[Omega], c]^2 y[ t] == -Subscript[\[Omega], c]^2 Subscript[v, d]*t + Subscript[\[Omega], c]*Subscript[v, 0], y[t], t] Out: {{y[t] -> C[2] Cos[t Subscript[\[Omega], c]] + C[1]...

What are the normalizations constants of psi(x) in a finite potential box? is there an algebraic or analytical solution. I have the solution to the infinite box but it seems the two cases are not comparable. As in the finite box the particle does not need to be in the box?

I have five generators of a lie algebra, g_1,g_2,g_3,g_4,g_5 which at first glance I believe are independent, although I could be wrong. I have calculated the structure constants, i.e. \left[g_i,g_j\right]=f_{ij}^k g_k And from that I have calculated a matrix rep using...

from where do chlorine monoxides form? I'm asking this because I'm just wondering if there is a way to direct all the oxygen radicals on its way to react with ozone to a whole bunch of chlorine monoxides to form oxygen gas. Is that possible or what? I'm a guy who likes to teach.

Homework Statement The exam grades in a certain class have a Gaussian PDF with mean m and standard deviation \sigma. Find the constants a and b so that the random variable y=aX+b has a Gaussian PDF with mead m' and standard deviation \sigma'. Homework Equations The Attempt at a...

A scientist wishes to find the age of a sample of rock. Realising that it contains radioactive potassium, which decays to give a stable form of argon, the scientist started by making the following measurments: decay rate of the potassium in the sample = 0.16Bq mass of potassium in the sample...

technically it is not homework, more like struggling with textbook material, but something tells me it would end up here anyway so here it is : there's something about the method that gives me different results using different paths so I'm going to show both of them and see if you can spot the...

Two identical massless springs of constant k = 200 N/m are fixed at opposite ends of a level track, as shown in Figure P5.62. A 5.90 kg block is pressed against the left spring, compressing it by 0.150 m. The block (initially at rest) is then released, as shown in Figure P5.62a. The entire track...

Just a quick question: the transition between pre-big bang to post big bang (if it occured) required a change in physical constants (our universe is ever-expanding while the preBB universe was not). How can these constants change themsevels into new constants like that? This would seem to...

Hi there, Does anybody know how to exploit the product of structure constants of SU(N) through Kroenecker deltas? I mean \sum_a f_{abc}f_{ade} I know this for SU(2) as in this case I have the Levi-Civita symbol but in other cases I was not able to recover it in literature. Any...

Homework Statement i'm trying to find two constants in the same equation. its an initial value problem there's a two parameter family x=c1cost+c2sint with initial conditions x''+x=0, x(pi/6)=1/2, and x'(pi/6)=0 so I'm trying to find c1, and i equate the problem to 1/2 and subsitute...

Does anyone have information on temperature dependence of dielectric constants? I haven't been able to find anything general enough on Google. I'm particularly interested in Polyethylene, Teflon, and Air but a general description would also be appreciated.

A rocket is fired at an angle from the top of a tower of height 50.0m. Because of the designs of its engines, its position coordinates are of the form x(t)=A+Bt^2 and y(t)=C+Dt^3, where A, B, C, and D are constants. The acceleration of the rocket after 1.00s after firing is a=...

Homework Statement I have been puzzling over this question for hours now. The centre of a wall clock is 180 cm above the floor. The hand of the clock that indicates the seconds is 20 cm long. The height, h cm above the floor, of the tip of the second hand, t seconds after midday, is...

SU(2) and SO(3) "have the same Lie algebra". While I understand that their corresponding lie algebras su(3) and so(2) have the same commutator relations \mbox{SO(3)}: \left[ \tau^i, \tau^j\right] = \iota \varepsilon_{ijk} \tau^k \mbox{SU(2)}: \left[ \frac{\sigma^i}{2}...

Hello, When the fine structure constant (a) is calculated from the electric and magnetic constants. What does each part represent. (1/c) * (1/electric_constant) * (e^2/(2*h)) = a i.e. What does (1/electric_constant) represent? The opposite of vacuum permittivity?And with the...

Homework Statement A 70 kg bungee jumper leaps off a bridge. She is tied to a 12 m long bungee cord and falls a total of 31 m. Calculate: a) the spring constant of the bungee b) the maximum acceleration experience by the jumper Homework Equations F = kx Eg = Ee where g is...

I recently read a thread that pointed to some constants that caught my attention. Before I go off the deep end with a question it would seem to be a good idea to understand exactly how constant are certain constants. I'm specifically curious as to the constants of: Length of a day (sidereal...

Hey folks, I am trying to generate the Pauli matrices and am using the following formula taken from http://en.wikipedia.org/wiki/SU(3 ) "In the adjoint representation the generators are represented by (n^2-1)×(n^2-1) matrices whose elements are defined by the structure constants"...

Homework Statement Find constants c1 and c2 such that F(x) = c1xsinx+c2cosx is an antiderivative of f(x) = 4xcos(x)+3sin(x) Homework Equations d/dx cosx = -sinx d/dx sinx = cosx The Attempt at a Solution Don't know how to setup or handle a problem such as this. Prolly much simplier...

Hi, can someone help me on the following question. Equilibrium constant=0 Equilibrium constant=1 What are the significance of these 2 values? As in, what is happening to the reactants as well as the products in this 2 instances? Thank you!

Homework Statement Consider a Rocket in space, far removed from external gravitational influences, and suppose the engine starts up. As long as the engines are running, its instantaneous velocity v is a function of its mass. V is given by: V = A + B log(D/m) A, B, D are physical...

Homework Statement How can I determine the phase constant of the these graphs? I am kind of confused about phase constant and its physical meaning, so if someone could explain it to me, I would be very grateful. Homework Equations The Attempt at a Solution

I have two Lie algebras with structure constants f^{a}_{bc} and g^{a}_{bc}, the number of generators being the same (as will become clear). Due to a particular symmetry/construct, I have that the system needs to be valid under g \to af + bg (and a similar transform for g), which leads...

Procedure: 1. Pipette 25 cm3 of ethanoic acid into a conical flask 2. Titrate against 0.1M sodium hydroxide solution in the burrette, using phenolphthalein as indicator. 3. Pipette further 25 cm3 of ethanoic acid into the solution after titration and mix throughly. Questions: 1. what is...

If the physical constants vary from universe to universe in a multiverse, then if matter from this universe were to somehow go into another universe, say through a wormhole, what would happen to it? Would it disintegrate, or somehow behave strangely? What if the cosmological constant varied in...

Does anybody know where I can find the value for the Lenard Jones potential constants (sometimes denotes as A and B, sometimes as Sigma and Gamma) for specific molecules and/or solids?

I'm not looking for the complete answer (from what I've read in the intro posts, you won't/shouldn't give it to me anyways)... I just need to figure out where to start. This is my first time taking calc, and I'm pretty lost. Thanks in advance. Homework Statement Find the values of the...

RC Circuits! A capacitor in a single-loop RC circuit is charged to 63 % of its final voltage in 1.5 s. Find (a) the time constant for the circuit and (b) the percentage of the circuit's final voltage after 3.5 s. Given that V/Vo = 63%, t = 1.5 sec , Time constant =τ Now...

http://www.nature.com/news/2007/071220/full/news.2007.389.html this just came out in Nature News, comment? To be sure, they are talking about how many DIMENSIONAL fundamental constants you need. The main bunch of constants that people always want to measure and to explain are the...

How much water does Lee Smolin's theory of fecund universes hold? Also, according to his theory, the basic parameters of nature vary between universes. My question is - how much? Is it a noticeable difference that would make life as WE know it impossible?

I'm in a hurry so I'm going to say this quick. For angular momentum you have [J_i ,J_j ] = i\hbar \varepsilon _{ijk} J_k and for isospin you have [t_i,t_j] = ig\varepsilon_{ijk}t_k now, \hbar is viewed as a constant, but g is allowed to change it's value due to renormalization...

Hi all, I'm a physics teacher at an australian high school, and some kids that I teach have give me some interesting data reguarding spring constants. They made a contraption to project marbles as part of an analysis of projectile motion, and part of the contraption was a spring, used to...

Something I've always wondered: how did Physicists and Mathematicians of years past discover equations with these integer (and even fraction) constants in them? Take for example the mean-square-speed equation: \mu \equiv \sqrt{\frac{3RT}{M_{m}}} or Kinetic Energy: \frac{1}{2}mv^{2} How...

[SOLVED] Constants Of Motion A Particle of mass m moves in three dimensions under the action of a conservative force with potential energy V(r).Using the sperical coordinates r, \theta,\phi, obtain the hamiltonian function for the system. Show that P_{\phi} , \frac{P^{2}_{r}}{2m} +...

Homework Statement Preliminary questions: 1. John's weight is 618 N. He is sitting on a bosun's chair which is suspended from a spring. John's feet are pressing vertically down on a bathroom scale which reads 45 kg. What force is John exerting on the bathroom scale? Correct, computer...

Solve the following linear system: ix + (1+i)y = i (1-i)x + y - iz = 1 iy + z = 1 I am getting nowhere with this. is there a trick to do these? I keep getting more and more variations of i. like i^2-1, and (1-i^2)-1 ix + (1+i)y=i (1-i)x + y-iz=1 y + z = 1 ix + (1+i)y = i i(1-i)x - (i^2-1)z =...

Homework Statement "K" is the time derivative of acceleration. Assume initial conditions of Ao, Vo, and Do.("o"=initial). Find: a(t): v(t): d(t): Show that: af^2=ao^2+2J(Vf-Vo) Homework Equations I'm honestly lost on this one..I don't know where to start. I could probably...

Homework Statement Evaluate the limits in the terms of the constants involved: \lim_{x \rightarrow a} \frac{(x+a)^2-4x^2}{x-a} Homework Equations The Attempt at a Solution First I plugged in a to make sure it was indeterminate and it was it ends up being 0/0. So I...

Homework Statement solve: y'=(x+y-1)/(x-y-2) i.e Homework Equations The Attempt at a Solution let y=vx thus y'=v'x+v by substitution: v'x+v=(1+y/x-1/x)/(1-y/x-2/x)=(1+v-1/x)/(1-v-2/x) v'x=(1-1/x+v^2+2v/x)/(1-v-2/x) still can't separate the variables...any...

0, 1, phi (the Golden ratio), e, pi, delta (Feigenbaum's constant) and comparatively many other fundamental, dimensionless mathematical constants occur on the interval 0 to 5. With a potential infinity of numbers to choose from, why does such a confluence exist?

Homework Statement For type 1, 2, or 3 projectiles, which of the following are constant? Dx, Dy, Vx, Vy Homework Equations The Attempt at a Solution I figure that the only one that is constant in all situations would be Vx because there is no acceleration in the x...

Basic engineering question. For any average spring (say, in an industrial setting), is the spring constant in compression about equivalent to the spring constant in extension?

Are normalisation constants in physics always real valued? If yes, is that because the normalisation constanst only normalises measureable quantities which are always real so the constants are real also. Any exceptions?

I just need some help understanding some of the theory behind these.. Can anybody help explain the relevance of a time constant in an RC circuit and why the time constant increases as resistance increases? Thanks in advance:blushing: