Question 12/98

COUPLED PENDULUMS

Two pendulums with equal masses m are coupled by a spring with spring constant k as shown in the figure. Length of the left pendulum is l, while the length of the right pendulum is different: l+x. The length of the right pendulum can be varied. Assume that at the initial moment the right pendulum is shorter than the left one (x<0). We deflect the left pendulum and release it. The system starts oscillating. Now we gradually increase the length of the right pendulum until it is longer than the left one. How will the system behave at the end of this process?

This question was suggested by S. Nussinov.

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