The Bat   The baseball bat is quite a unique piece of equipment Have you ever wondered why so many baseball bats get broken during a baseball season? Well, like all things in nature a baseball bat has a natural resonance frequency, and since bats are not totally stiff objects they will vibrate. Although this may not be felt every time, there is always some vibration. That vibration is determined by the amount of oscillation, and the oscillation is determined by the frequency and the amplitude. The frequency and amplitude will be determined by where the ball hits the bat. Two waves will be generated, one where the ball hits the hat and one where the ball leaves the bat. The waves look like this:   http://library.thinkquest.org/11902/physics/vibrate.html   The place where the two waves meet are called the nodes. The nodes are called points of destructive interference, and the places where the two waves are furthest apart are the anti nodes. If the ball hits the anti node, the bat will break or string. Anti nodes are the points where the maximum amplitude will be generated. At nodes, the two waves will cancel out stopping the oscillation. The node is the sweet spot of the bat, and the anti nodes are the end or middle of the bat.