Perturbation Theory

  • Thread starter Nusc
  • Start date
  • #1
753
2

Homework Statement


The length of a pendulum is slowly doubled (l=l_0(1+epsilon*t), 0<=t<=1/epsilon). How does the amplitude q_max of the oscillations vary?

Any hints?


Homework Equations





The Attempt at a Solution

 

Answers and Replies

  • #2
100
1
Are you changing the total energy? By how much?
 
  • #3
753
2
I'm not sure...


Ans. I = 1/2 * l^{3/2} * g^{1/2} *q_max^{2}.

therefore

q_max(t) = q_max(0)(l(0)/l(t))^3/4
 

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