Conical Swing of a Pendulum and Centripetal Forces

This experiment uses a conical pendulum to familiarize us with dynamic equilibrium in rotational motion. In this investigation, we will identify the free body diagram of a horizontally whirling object and see how it lifts as its speed goes up. The lift apparently defies the downward pull of gravity, but we will see how a delicate balance of forces allows the object to swirl at a certain lift angle. As the speed of the object changes, the forces adapt and preserve the delicate balance. Eventually, this apparatus becomes a really nice demonstration of the interplay of geometry, vectors, forces, and equilibrium. This experiment recreates the mental problem in Paul Nahin's beautiful book, "In Praise of Simple Physics" and is one of the author's methods to determine the value of g.