Combination Definition and 525 Threads

Hello, I am trying to derive the TISE, but I am having many questions, and the textbook (Griffiths) does not give any adequate explanation and I have minimal access to my professor. My goal is to find ##\Psi (x,t)##. The book says the solution is $$ \Psi (x,t) = \sum_{n=0}^{\infty} c_{n}...

In a combination circuit, with 2 components, if the voltages across each is the same, why must the resistance of the components be equal to each other?

Hello all A simple question. It is known that \[\left ( \begin{matrix} x_{1}\\ x_{2}\\ x_{3} \end{matrix} \right )\] is a solution of a homogenous system of equations. I need to determine if \[\left ( \begin{matrix} x_{1}+1\\ x_{2}+1\\ x_{3}+1 \end{matrix} \right )\] is also a solution...

Homework Statement Find a set of basic solutions and express the general solution as a linear combination of these basic solutions a + 2b - c + 2d + e = 0 a + 2b + 2c + e = 0 2a + 4b - 2c + 3d + e = 0 Homework Equations 3. The Attempt at a Solution [/B] i reduced it to: 1 2 0 0 -1 0 0 0 1...

I, II represent rows 1 and 2, respectively. I am not agreeing with these solutions at step 3 of 5, where they multiply row 2 by 1/(b-a). Correct me if I'm wrong, but we do not know if b-a=0, so I do not think we can divide row II by (b-a) because of the potential of dividing by 0? What do you...

Hey guys, there's these questions in my hm that's really tough for me and i basically have no clue on how to do it. Any help is greatly appreciated 1.a) Give the numbers 1,1,2,3,4,5,5,6,7, If five numbers are randomly selected without replacement, how many different numbers can be formed if...

Hi, i am trying to find the variance of the following: y*(s+n), where y is a m \times 1 vector following a chi-squared distribution with 2k degrees of freedom, s is a m \times 1 vector following a Gaussian distribution with zero mean and unit-variance, and n is a m \times 1 vector following a...

Homework Statement Write the vector u=(2,3,-1) as the sum of two vectors, one parallel to v=(1,0,-3) and the other orthogonal to v=(1,0,-3) Homework Equations orthogonal vector would imply that v"dot"w = 0 ( dot product) Parallel vector would imply that v=kz OR the crossproduct of both is 0...

Hello Guys, I need little help currently I am working with on a Project that includes Motor Pulley and rope combination. The previous version of our Test bench was having a Motor pulley and rope and the rope was wrapped around the pulley as in most of the cases, but now I am trying to optimize...

Does anyone know where I can go to figure out how to generate a random 3-4 letter sequence BUT with every click that sequence is stored in an array and can not come up again?

Homework Statement In how many ways can one choose 6 cards from a normal deck of cards so as to have all suits present?Homework EquationsThe Attempt at a Solution 4 different cards can be chosen in 13*13*13*13 ways. Now we have to choose 2 remaining cards from 48 cards. This can be done in...

1) When we learn about MO theory, we learn that there are different ways to combine atomic orbitals to find the molecular orbitals for a molecule. However, going back to the fundamental/physical meaning of orbitals, orbitals are the wavefunctions. Wavefunctions do not have any physical meaning...

I am a 15 year old who is obsessed with math...anyway, I developed an equation dealing with safe combination possibilities. For example, if you have a safe with 5 digits, and you know there is (for example) a 4 and an 8 in the combination. You aren't sure which position they are in, and they can...

Homework Statement A small company gives bonuses to their employees at the end of the year. 15 employees are entitled to receive these bonuses of whom 7 employees will receive 100$ bonus, 3 will receive 1000$ bonus and the rest will receive 3000$ bonus. In how many possible ways these...

I've seen it often taught that the combination of two vectors is their graphical sum, but I think that there is a problem with this, in that if the vectors have opposite-facing components, then there are portions of the vectors completely neglected by the calculation. The idea seems to only be...

Hey! (Wave)I am looking at the Knapsack problem. (Nerd) We have a sack,that has a capacity of objects with total cost $W$. There are $n$ objects with weights $ w_1, w_2, \dots ,w_n$ and values $ v_1, v_2, \dots , v_n$. Which is the most valuable combination of elements,that fit in the...

I was looking at this problem. Does the problem assume that the focal point of the divergent lens is right next to it? The answer is c, saying that the focus point will be further away: but that assumes that the focal point is not RIGHT NEXT to the divergent lens. If it were RIGHT NEXT (VERY...

Dear All, like subsets {abc} can be found out using binary digits like 000 001 010 etc etc. how can i find the order of element for any combination which can be calulated useing following formula. n!/r!(n-r)! yours sincerley

Dear All, There are three numbers they can have two status "a" or "b". only one status can exist at one time for a number. I have to chose three number(1,2,3) , they will be in this order only. , so please tel how many combination can be there? 1(a) 2(a) 2(b) 3(a) 3(b) yours sincerley

So what if we have two thick lenses? Thanks in advance ,

I'm working with matrices, so maybe this should be in the calc and beyond, but my problem is with the algebra (-.-) I've reduced my matrix to this: ##(b-a)(c-a)\left | \begin{array}{cccc} 1 & (b-a)^{-1} & (c-a)^{-1} & 1 \\ 0 & 1 & 1 & (d-a) \\ 0 & 0 & (c+a) - (b+a) & (d^2- a^2) - (b +...

Hey guys, I'm reading the Theory of Sound and I've come to a part in which I'm having trouble double-checking the algebra. Suppose we have two harmonic sound waves of equal amplitude traveling directly perpendicular to each other. \begin{align} u=acos(2πnt-ε) && v=bcos(2πnt) \end{align} They...

Hi, An ice cream shop sells ten different flavors of ice cream. You order a two- scoop sundae. In how many ways can you choose the flavors for the sundae if the two scoops in the sundae are different flavors? That's what I did : 9+(9-1)+(9-2)+...+(9-9)=45 Would this be any good ...

I know that if you have 4 numbers eg. 1,23,4 then the total number fo diffferent combination is 4*3*2*1 = 24 what about if one number is the same eg. 1966 Thank you

Homework Statement If I have 3 2V and 1A supplies, and I want to test at 5V, how will I setup? Homework Equations The currents add up when connecting the supplies in parallel, and the voltages add u when connecting in series. The Attempt at a Solution I tried different...

Homework Statement how many ways can ##a,b,c,d,e,f,g,h,i,j## (first ten letters of the alphabet) be interchanged if ##a,b,c## must be adjacent and if ##d## cannot be touching the ##a## nor can it touch the ##b##? The Attempt at a Solution to start, i figure we can take the total number of...

Why did the author of the book choose the combinations in (9.66) and (9.67) as follows? Why didn't he choose some other combination; say 1/sqrt(3) and the other 2/sqrt(3) instead of 1/sqrt(2) and 1/sqrt(2)? Please see attachment. Note that this is problem on stark effect.

Homework Statement a) How many different initials can someone have if a person has at least two, but no more than five, initials? You may assume that each initial is one of the 26 uppercase letters of English, and that letters can be repeated. b) When attempting to name his son, Jor El...

Homework Statement http://imgur.com/h5VXibe Have to solve V, I, R and Power for all resistors and the circuit total. Known data is shown in table. The rest needs to be solved for Homework Equations Ohm's Law and Series Equation: 1/Er=1/R1+1/R2... and Tr=R1+R2...The Attempt at a Solution...

Generally for bathing purpose, we heat water to higher temperature say T1 than the temperature at which body is comfortable say T0 (is T0 = 70 degree Celsius?) & add some quantity of cold water to it to have the temperature of water = T0. Is the process energy efficient? What is the best...

Homework Statement The question is attached as a picture. Note: if someone would prefer I type it out I can. Homework Equations Schrodingers equation The Attempt at a Solution PART A I am pretty sure I got the well right. It looks like a finite well inside an infinite well. I...

How come the combination of C(70,67) is 54,740?

Homework Statement let r be an element of R ... 1.... 1 ......r^2.....3 + 2r u =( 1 )...v = ( 4 )...w = (1 )...b = ( 5 + 12r) ...0.....1......r^2 ...... 2r (sorry don't know how to type matrices) 1. For which values of r is the set {u, v, w} linearly independent? 2. For which...

Homework Statement The equation \psi(x) = \frac{1}{sqrt(2)}\psi_0 (x) + \frac{i}{sqrt(5)}\psi_1 (x) + \gamma\psi_2 (x) is a combination of the first three eigenfunctions in the 1D harmonic oscillator. So, \psi_0 = Ae^{-mωx^2 /2\hbar} and so on for the first and second excited states. If...

Homework Statement In how many ways can 8 different things be divided into groups of 5 and 3. Homework Equations The Attempt at a Solution I thought it be just be 8C5 X 8C3 but also might it be 8C5 x 3C3 since if you take 5 you only have 3 left to select from?

Homework Statement Linear combination is \hat{A} + i\hat{B}. It's given that it is not Hermitian already. Homework Equations ∫ψi * \hat{Ω} ψj = (∫ψj * \hat{Ω} ψi)* The Attempt at a Solution ∫ψi * (\hat{A} + i\hat{B}) ψj = (∫ψj * (\hat{A} + i\hat{B}) ψi)* I chose to work with...

Hello, I am trying to compare different combinations of Radiators and fans on their ability to cool water(or any liquid for that matter) Now I've been showen some Bernoulli's equation things and been pointed at Reynolds number but To be honest I haven't looked at any physics outside rigid...

Homework Statement Combinations of Resistors Im not sure if the image will show up. If the image doesn't show up; it is similar to this picture http://www.ceb.cam.ac.uk/data/images/groups/CREST/Teaching/impedence/sparal6.gif In the link's picture R1 is in the correct spot, R2 is R6-5-4 and...

Hello Everyone! I am working my way through Gilbert Strang's book on linear algebra. I came across a set of solutions to the problems whose solutions are not listed in the book http://www.scribd.com/doc/86849289/1/Problem-Set-1-1-page-8. However, as I was working on the following question: I...

Homework Statement Determine the Req, IT, and the current and voltage across each resistor. Collapse each drawing into one resistor that equals Req. Find the total power used by the circuit. Also determine the voltage, current, and power for each individual resistor. The one I'm having...

Homework Statement Two projectiles are launched simultaneously from the same point, with different launch speeds and angles. Show that no combination of speeds and angles will permit them to land simultaneously and at the same point. The Attempt at a Solution I have a rough idea...

Homework Statement I am given a linear combination of wave function of HYDROGEN ATOM Ψ=1/2(Ψ200 +Ψ310+Ψ311+Ψ31-1), where the subscripts are n, l, m respectively. I was asked to find all the possible outcomes when measuring Lx and their corresponding probabilities. Homework Equations...

Capacitors , why can't series combination be used in an open circuit?? they say we cannot apply series combination formula for the capacitors in an open circuit,,,but why?? why can't we find the equivalent capacitance in an open circuit?

Homework Statement Two capacitors A and B with capacitance 3 μF and 2 μF are charged to potential difference of 100 V and 180 V respectively. These two capacitors are connected to an uncharged capacitor of 2 μF using a switch as shown in the diagram. Determine the final charge on each...

Reviewing for my final exam can anyone please help access these problems? a) How many ways can 11 football players stand in a circular huddle? I put 11P11 b) 12 identical laptops are in the inventory of a dealer, and 2 have hidden defects. If 5 computers to be shipped are selected at random...

Homework Statement three resistors R1=R2 and R2=2R3, are connected to a battery, as show in the figure, if the power dissipated for each one is p1,p2 and p3 respectirvely;p3 must be equal to: Homework Equations P=VI P=V^2/R P=I^2*R The Attempt at a Solution I have tried to...

Hello, I'm trying to solve a combination problem and am uncertain what kind of combination exercise this is. It's not school work, but something I came across in my free time, and I'm somewhat stuck... I have three pots, each with 20 balls. I want to create all combinations possible by...

Homework Statement Two pulleys are mounted on fixed axles that have negligible friction. The small pulley has a moment of inertia of 9.0 kgm^2, and is made of up of two cylinders wielded together, one of radius 7.0 cm, and one of radius 15.0 cm. The large pulley has a radius of 41.0 cm, and a...

Homework Statement Find the ##gcd(x^3+x^2-x, x^5+x^4+2x^2-x-1) ##and write it as a linear combination. Homework Equations The Attempt at a Solution I know the ##gcd(x^3+x^2-x, x^5+x^4+2x^2-x-1)=1## What I have so far is ##1. x^5+x^4+2x^2-x-1=(x^3+x^2-x)(x^2+1)+(x^2-1)## ##2...

Homework Statement Prove: \sum^{n}_{r=0}2r(^{n}_{r}) = 3n Homework Equations The Attempt at a Solution I proceeded by induction: Testing the base case for n=0 is correct. Moving right along to try to show: \sum^{n+1}_{r=0}2r(^{n}_{r}) = 3n+1 This is where...