Forces on a Baseball

A baseball may look simple, but a host of complex physical forces take charge of the 3-inch ball when play begins. Size and weight have as much to do with the baseball’s flight pattern and velocity as the hand throwing it or the bat hitting it. And we know this because of the laws of physics. Whether a ball is thrown or hit a ball in flight is governed by three major forces. The first is gravity, which exerts a continuous downward force – you know what they say, what goes up must come down. Another is drag force. This is the air friction encountered by a ball in flight. Air acts just like a fluid, which impedes the ball's path, so as a pitch is thrown, air works against the ball to slow it down. Now, these stitches aren’t just here for decoration they break up the air flow, which actually reduces drag and enables the ball to fly further than if it was smooth all the way around. The third force determines a ball trajectory. Magnus force describes the imbalance of air flow past the spinning ball. When a ball spins, air is forced to move faster in the direction of the spin. The faster flow results in lower air density and causes the ball to move in that direction. Sounds complicated but all you need to know is that the balls flight path, determined by its rotation. Scientists have been so intrigued by the effects these forces have on a ball that they've used wind tunnels, strobe photography and other sophisticated technology to study them. The biggest question they wanted answered was whether a curve ball actually curves or whether it's just an optical illusion. After years of debate and published reports, from both sides, the latest tests conclude that- yes the ball does curve as much as 18 inches for a skilled pitcher. And that's what makes the curveball so hard to hit. Now, all scientists need to figure out is how to hit the darn thing.