Mors dira fuit, vita salusque patent.

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"Where grim death has been, life and health appear."

The short story, The Pit and the Pendulum by Edgar Allan Poe, remains a masterful work of psychological narrative writing, but for the careful reader, it also is a wonderful source of some interesting computational problems.

As the imprisoned narrator recalls various tortures, careful observations about the size and physical properties of the pendulum that seems doomed to slice him also allow him to focus his efforts to escape, if only there is enough time left to effect a plan. Knowing just how long or short a time the prisoner had to escape can add to the growing sense of horror and suspense:

"I saw that some ten or twelve vibrations would bring the steel in actual contact with my robe- and with this observation there suddenly came over my spirit all the keen, collected, calmness, of despair."

We encourage you to explore these questions by observing the differences between a simple pendulum and a physical pendulum.

Consider the expressions for the period of one oscillation for varions models:

• A simple pendulum of length L under the influence of gravity g with small-angle oscillations:
  
• The same simple pendulum, when the oscillations are not so small:
  
• A physical pendulum of moment of inertia I and total mass m rotating around a point a distance h from the center of mass with small-angle oscillations:
  
• The same physical pendulum when the oscillations are not so small:
  

In the expressions above, k is defined as: