The Ratio Of The Lengths Changes

1724 Words Jun 16th, 2015 7 Pages
Question 1: What happens to the motion as the ratio of the lengths changes? (Thinking)

If you decrease the length of the top one (L1) =0 then L2 becomes a simple pendulum and undergoes simple harmonic motion.

If you increase L1 more, then l2 undergoes faster chaotic motion and if you decrease the length, it will become less chaotic.

Question 2: At first glance, why does there appear to be much more energy in the pendulum than was put into it when it was released? (Communication)

There are a few reasons why it seems like that.
First, the pendulum was started with a push rather than dropped, so that will put more energy into the system than it perhaps seems like there should be.
Second, the lower the pendulum is, the less potential energy it has, so the faster it will go. When the long leg is low, there is enough energy for the shorter leg to move very quickly, especially if the long leg isn 't moving very quickly. Some of the fastest movements of the short leg happen when the long leg is near the bottom of its path.
Third, the short leg is smaller than the first leg. This means its mass and especially its moment of inertia will be a good deal lower than those of the long leg. Also, when the long leg slows down, the short leg slows down too, even though it’s hard to tell. The short leg has two rotations going on, one that is centered at its end, and one that is due to the long leg rotating. All of this together means that small changes of speed for the long leg can…
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