1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The wave fuction for particle in a box

  1. Oct 4, 2013 #1
    Whwn i am doing exercise, i dont know how to solve the follow question by myself Although i hv the ans, i want to complete it by myself. Plz give me some tips only so that i can finish this question, please also tell me how do you know the question should be solved in this way.

    The question requires me to solve the wave equation for a pacticle in a infinity potential well, from x=-l/4 to x= 3l/4
    I let the wave equ be the form
    Asinkx + B cos kx

    and i got.
    Asin(-kl/4) + B cos (-kl/4) = 0
    and
    Asin(3kl/4) + Bcos(-3kl/4) = 0

    and than i cant do anymore
    it is different from to x=0 to x= a case
    What should i do? Any tips?
    Is there any general solution for the wave fuction of the pacticle in a box from a point x to y?
     
  2. jcsd
  3. Oct 4, 2013 #2

    clem

    User Avatar
    Science Advisor

    Change the variable to u=x+1/4.
     
  4. Oct 4, 2013 #3
    thinks i am now trying to calculate
    Could you plz tell me why u know that the varible should be changed? Due to the experience? I am not good at physics but i love it should i do more exerience to develope this sence?
     
  5. Oct 4, 2013 #4
    sorry
    i dont get it
    where should i change varible
    do u mean that i should differinate the fuction?
    I cant normalize it caz i dont know A abd B
     
  6. Oct 4, 2013 #5

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    clem meant "let u= x+ l/4" (it's a little difficult to distinguish between "l" ('ell') and "1" ('one') depending upon which font you use.) The only purpose of that is to change the boundaries from x= -l/4 and x= 3l/4 to u= 0 and u= 1 which makes the arithmetic slightly easier.
     
  7. Oct 4, 2013 #6

    Bill_K

    User Avatar
    Science Advisor

    Script ell is easier to read, one reason I use UTF.
     
  8. Oct 4, 2013 #7
    Thank you guys. I got the answer. This skill is really useful for dealing with waves in the box.
    The answer is : fuction = A sin (kx + kl(ell)/4) and A = root(2/a)
    am i correct?:)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: The wave fuction for particle in a box
  1. Particle in a box (Replies: 7)

  2. A particle in a box. (Replies: 4)

  3. Particle in a Box (Replies: 8)

Loading...