We recently attended the American Association for Engineering Education meeting in Louisville, KY. While there, we had a free afternoon, so we went to the Louisville Slugger Bat Museum. In the museum, they had an exhibit where they asked you to hold a baseball bat vertically, suspended by the knob, and then to tap it with another baseball bat at different spots along the bat. The idea was to see if you could find the “sweet spot,” which is the center of percussion—where the rebound force of the bat is completely balanced out by the force of the ball. When the bat hits the ball at the sweet spot, the batter will feel very little vibration in the handle from the impact.
Michele Perrin, a teacher who works with us on projects in the summers, came up with the idea of mounting one of our Low-g Accelerometers, on the knob of the bat and monitoring the vibrations, while we do the tapping. Here are some results: