Swing a Pendulum in PowerPoint

Swing a Pendulum in PowerPoint: "Creating a pendulum swing animation is possible using PowerPoint 2002 or later - and involves creating a hidden pivot point. A pendulum (the real type) swings back and forth on a pivot point at the top of the weight's string, so we will need to create a shape that appears to swing at the end of a string and repeats back and forth from this pivot point. Here are the steps"