Elastic behaviour in the horizontal direction can be described by a tangential coefficient of restitution, which is about 0.5 or 0.6 for a superball but only about 0.2 for a baseball on a rigid surface. The player will swing the bat from low to high, with too much bat speed resulting in fly balls. The sweet spot of a bat exists because bat vibrations are not excited significantly at that spot. A ball that would travel 400 feet in "normal" conditions goes: 6 feet farther if the altitude is 1,000 feet higher 4 feet farther if the air is 10 degrees warmer 4 feet farther if the ball is 10 degrees warmer 4 feet farther if the barometer drops 1 inch of mercury 3 1/2 feet farther if the pitcher is . 2 0 obj There is enough physics in it to keep a PhD student busy for a few years, but it could also be done by any high school student as a simple introduction to the physics of baseball. The tubes were suspended by a length of string so that they could vibrate for a long time without damping. He has been writing about the sport for over five years and is passionate about sharing his knowledge and enthusiasm for the game. } Movies showing the collision of a baseball with a cricket ball and the collision of two billiard balls are shown in the page on collisions. At room temperature, it will go from a solid to a gas directly. The direction of the centripetal force is toward the center of the circle followed by the path of the CM. The impacts were at distances of 2, 7, 12, 17, 24 and 31 cm from the end of the barrel. The mode shape of a baseball or softball bat is a simple flexing bending shape that has parts that move and parts that don't. Every bat has a point about seven inches in from the tip of the bat that doesn't move, that doesn't vibrate, called a node. When a very light bat is swing velocity at maximum, it has little power to transfer to the ball. Not exactly like a drum, more like a bell or a chime, but the effect is similar. The popularity of maple bats has increased dramatically since the introduction of the first major league-sanctioned model in 1997 due to their hardness, durability, and performance. >> If the ball is struck at the sweet spot of the bat, then the batter feels almost no effect at all. But I would expect there to be a difference.. Players tend to feel a zing in their hands; often called bat sting. If you hit a baseball somewhere other than the sweet spot, your hands will feel the vibrations. The force on the bat can be worked out from the velocity of the center of mass, (CM), and the torques can be worked out from the angular acceleration. Some results for an Easton BK7 aluminum bat are shown below in 13 QuickTime movie files, each about 1 Mb. We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. Whenever an object is struck, it vibrates in response. Analytical cookies are used to understand how visitors interact with the website. /ColorSpace [/Indexed /DeviceRGB 255 28 0 R] Every bat has a sweet spot.. The weight of a bat can be calculated by subtracting the minus number from the length, which in this case is 33 minus -3, equaling 30 ounces. The ball rotated more than 1/4 but less than 1/2 of one revolution from one frame to the next, each frame being 0.04 sec apart. 5P8$ BaPR+"dUkbQ]YH`P. In recent years, an acoustics professor and engineer, Daniel Russell, from Pennsylvania State University helped, Bat-Ball Science Mass Moment of Inertia article, The Science Behind Breaking Baseball Bats, Characterizing the performance of baseball bats, Performance versus moment of inertia of sporting implements. 7 0 obj /N 13 0 R >> [/CalRGB Washington State University Sports Science Laboratory, You can get into the real nitty gritty of the science of MOI including complex equations by clicking through to the complete Bat-Ball Science Mass Moment of Inertia article, but well put it in laymans terms. Taking the rotation rate as 3/8 revolution / 0.04 sec gives 9.4 revolutions / sec or 560 rpm. The ball rotated more than 1/4 but less than 1/2 of one revolution from one frame to the next, each frame being 0.04 sec apart. Despite the old timey aesthetic to wooden bats and sweet spots, scientists actually didnt know much of anything about the acoustics (yes, acoustics) of a bat until the 1980s and 90s. Scientifically speaking, this is the weakest part of a wooden baseball bat. In bats made of maple wood, like the Axe Bat, it's easy to find the strongest grain. See, the trouble with wood is that it vibrates. Is it possible to hit heavier bats harder? So, if you make sure the label is up, it means that you will be making contact with the edge of the grain which is the strongest part. The bat then magnifies that force by a factor of about 100-5,000 lb or so when it collides with the ball, enough to squash the ball in half. 10 0 obj /N 10 0 R /N 21 0 R In fact, if the ball strikes the bat exactly on the ``sweet spot'' then the hitter is almost unaware of the collision. /R [52 73 308 791 ] This includes both the length of the barreltop part of the batand its diameter The longer the barrel, generally, the larger the sweet spot for hitting the ball The standard diameter is 2 , and big barrel bats, allowed in some leagues, are 2 5/8. Hey, were not all headed to the majors. /P 20 0 R We use the idea that if a body collides with something, then its angular momentum is conserved with respect to the point of impact. To increase the acceleration of the ball while it is still moving, a bat that strikes it harder will most likely accelerate faster. When you use a heavier bat, the faster you hit the ball, the longer it will travel. You can actually hear where the sweet spot is just by tapping a bat yourself. A careful analysis of baseball dynamics shows that this special spot is located at the point where an applied force would result in pure rotation of the bat about the handle grip. >> The experiment described below would be an ideal project on the physics of baseball, for any high school or University physics student. The first is where the bat feels best in your hands when you hit. /V 22 0 R Depending on how the ball rotates, the wake may deflect. QuickTime movie files A and B show a baseball bouncing on a block of granite. window.mc4wp = window.mc4wp || { /V 10 0 R A baseball bat is shaped in such a way to have a "sweet spot." The sweet spot is due to the fact that the CP and the VN coincide. So grab your bat and lets dive into the science behind the swing! Their sweet spots are anywhere between 10.16 and 25.4 cm from the barrel end. Understanding the sizes of bats is critical to making the best choice for your game and the best bat for you. My particular research interests are two-fold: the physics of the baseball-bat collision and the flight of the baseball. 9 0 obj By combining the results of these two separate experiments, we can then work out what happens when a bat is swung at an incoming ball. endobj The impact of a bat and a ball is still not properly understood. /P 23 0 R If there is a force of 5,000lb on the ball then . The ball bounces backward spinning counter-clockwise. If the ball is also mounted as a pendulum, the experiment can also be performed in reverse, by swinging the bat at a stationary ball. According to Newtons third law, every action has an equal and opposite reaction. The physics of a baseball bat include the material of the bat, the length, weight, and shape of the bat, and the force of the swing. That is, a large fraction of the stored elastic energy in the wall is retained as vibrational energy in the bat. The science of magnetism, while not as well-known as the science of moving energy when a bat hits a ball, is still important in the game. << Adding to that is the fact that, When a ball player hits the ball with the bat, it produces an enormous amount of force on the bat in a split second the impact could mean up to. Newtons second law, which deals with the value of time, is also important in baseball. These cookies ensure basic functionalities and security features of the website, anonymously. Learn how the sweet spot correlates with movement and vibration. If the bat approaches a ball incident at speed v. Are heavy bats are more powerful than light bats? The bat is 84 cm long, and has a mass of 849 gram. 12 0 obj 21 0 obj Demonstrating the sweet spot of the bat in a talk I gave at Wrigley Field for University of Illinois alumni in 1997. A rough estimate would be that the ball rotates 1/4 revolution while it is in the pitchers hand, and while the hand moves forward say the last 0.2 m. If the hand moves forward at 10 m/s = 22.4 mph then it moves 0.2 m in 0.02 sec, so the spin rate would be 12.5 rev/s or 750 rpm. The heavier the bat, the higher the bats bat speed. These spots are also described in the physics of tennis page. On average, the sweet spot occurs between 5 and 7 in (12.7 and 17.8 cm) from the barrel end of the bat. q varies from about zero near the tip of the bat to about 0.2 or 0.3 further along the barrel, and needs to be measured for any given bat since it is usually too hard to calculate. The hitch is, no one knows for sure how close the optimal spot for hitting is to the sweet spot that players know and love. Adair provides a few answers in his book The Physics of Baseball but he does not give the directions or the torques. One of the definitions of the "sweet spot" is the location of the node at the barrel end of the bat. But opting out of some of these cookies may affect your browsing experience. . , 231-232 (2001). There are some models that include oak, but it is not as popular as maple or ash. 3. Near the end of the swing, the batter needs to exert a large negative couple on the bat, otherwise the bat will swing around too fast and strike the ball when it is aligned at the wrong angle. A baseball bat is typically between 30-34 inches in length and can weigh anywhere from 24-30 ounces. Baseball is a science that is based on fluid dynamics. A pitch produces a turbulent wake of air behind the ball. /BitsPerComponent 8 Current research on the physics and science behind the game of cricket centers on the performance of the batsmen and bowlers. To understand such collisions it is important to first understand the physics of a collision between one ball and another. White ash, sugar maple, true hickory, yellow birch, red oak, and Japanese ash are the six wood types that can be used in bats in Major League Baseball. The reversal of the spin in each bounce implies that there is some tangential elastic behaviour of the ball in a direction parallel to the block. Subscribe to get special offers, free giveaways, and once-in-a-lifetime deals. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. In case that didnt quite clear it up for you, lets break this down a bit. The collision of a bat and a ball can be understood by treating the bat as a heavy ball whose mass depends on the impact point. I tossed a 12 inch softball at very low speed and filmed the result, using two hands instead of one to increase the spin rate and to make sure the spin axis was horizontal. /V 5 0 R READ SOMETHING ELSE Table of Contentsshow A high performance bat has a strong trampoline effect and hence a relatively large COR. These vibrations travel in waves up and down the length of the object. Each baseball bat has a sweet spot due to vibrational physics. So, after a rainy day game, ensure your bat is dry before you store it. A batsman during a cricket game aiming his shot to hit the sweet spot of the bat. If the ball didn't bounce at all then COR would be zero. /R [52 73 308 791 ] Boxing. Registration on or use of this site constitutes acceptance of our Terms of Service. It is not quantum physics or relativity, but a very interesting problem involving the mechanics of colliding objects. 1) Hit with the label up Manufacturers always place the label on the face of the grain. produce and innovate modern day cricket bats. A recoil of the bat occurs when a ball collides with the bat, causing it to push back against it with equal force. A lot has been learned over the years but more experiments need to be done to better understand how the ball bounces and how much spin it acquires when it bounces. If the vibration frequency is less than about 1000 Hz, the end result is that ball comes off the bat at a lower speed than off a wood bat of the same weight and swing weight. Colloquially, a player who hits the ball solidly is said to have gotten the sweet spot of the bat on the ball. While the majority of baseball bats are constructed from wood, there are also metal alloy bats available for certain leagues. The sweet spot of a baseball bat, like that of a tennis racket, can be defined either in terms of a vibration node or a centre of percussion. The experiment described below would be an ideal project on the physics of baseball, for any high school or University physics student. The ball is spinning clockwise before it bounces and hits the granite block with backspin. The material of the bat can affect its performance, as lighter bats tend to be more responsive and have higher exit velocities. << How do you know if a bat is too heavy for a boy? This is the location of the bat that is generally regarded as the best spot for hitting the ball. Second, if players started using aluminum bats, every MLB record would be shattered within a year and the statistics of the game would be changed completely. Where on the bat is the ball struck with the greatest speed? 4) Good quality bat grip Investing in a good quality bat grip will help improve your grip and increase your odds of hitting the ball in the sweet spot which can reduce the chances of breakage. /P 8 0 R Both the swinging bat and the pitched ball possess kinetic energy, which is generated by the players who swing the bat and throw the ball. You can find the sweet spot by gripping the bat handle with one hand in the same place as when youre swinging. 1 inch in length is huge. Both papers can be downloaded. The ideal is the 110 turn model. For small swings of a pendulum, the incoming and outgoing speed of the pendulum bob is proportional to its horizontal displacement, so the relevant ball speed ratios can be measured directly off the film with a ruler. The whole mass of the bat is not involved in the collision, unless the collision happens to occur at the centre of mass of the bat. However. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. The direction of the centripetal force is toward the center of the circle followed by the path of the CM. Theres one where it feels good in your hands, one where the ball comes off the fastest. Furthermore, the tip is the lightest and least effective part of the bat. /N 12 0 R It is critical not only for the sake of performance, but also for the sake of safety. The wall of a bat is relatively heavy and returns only some of its stored elastic energy to the ball, keeping the rest to itself so it can ping as loudly as it wants to. A bat is similar to a racquet but there are some obvious differences. The bat is 84 cm long, and has a mass of 849 gram. endobj >> The majority of hitters take a stride when hitting, which helps the timing of their swing. The first is where the bat feels best in your hands when you hit. Rather, the physics depends more on the ratio of the bat and ball speeds, regardless of whether the actual speeds are around 1 mph or 100 mph. We can then ask a similar question. >> Two ounces doesnt seem like much but Ive seen it make a large difference. This cookie is set by GDPR Cookie Consent plugin. listeners: [], The frequency is typically between 1000 Hz and 2500 Hz, meaning that the wall vibrates in and out 1000 to 2500 times in one second. It is not easy to find information on the actual rate of spin of a softball in flight, but it is relatively easy to measure, at least at low ball speeds and low spin speeds. At other impact points, the impact is usually felt as a sting or jarring of the hands and forearm, particularly if the impact occurs at a point well removed from the sweet spot. Definition. Baseball Sweet Spot Science ScienceC 19.8K subscribers 19K views 6 years ago It turns out there's a lot of physics that goes into the sweet spot on a baseball bat! 24 0 obj According to Newtons second law of motion, the acceleration of an object equals the net force acting on it divided by its mass, or a = F m . The ball is 72 mm in diameter. So, why does the MLB still use wooden bats? Licensed under CC BY-SA 2.0, via Flickr Creative Commons. 18 0 obj One question that can be answered this way is "Where on the bat does the ball bounce best?" The above results are more or less as expected, in that light bats can be swung faster than heavy bats. Aluminum bats are believed to have longer sweet spots than wooden bats. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. When it comes to bats, one inch in length is equivalent to an ounce of weight. << Recent Research Highlights. Collisions.- 11.Bat Performance.- 12. The answer depends on how fast each bat can be swung. The effect of the hands on the centre of percussion is described in American Journal of Physics, 72, 622-630 (2004). Concentration. The sweet spot classification quantifies that as a batted-ball event with a launch angle ranging from 8 to 32 degrees. For a fastball, this wake gets pushed down, which then pushes the ball up .. A high-end bat is designed for major league hitters in the 31-to-32-ounce (878 to 907 grams) range. The bat was swung through an axis 143 mm from the knob end. The end result can be a greater ball speed off the bat, in the same way that a tennis ball bounces a lot better off tennis strings than off a hard floor. Rather, most coaches and others think in terms of wrist torque, which is probably much too small to provide the necessary large couple near the end of the swing The couple must come mainly from the two arms, not the wrists. The shoulders reach maximum speed first. If a player can maintain the same bat swing speed with a heavier bat, the heavier bat will produce higher batted ball velocity and an increase in distance. When selecting a bat for the major leagues, it is critical for players to select the best wood for their bat in order to maximize performance, durability, and longevity. When it comes to the distance traveled by a ball, speed and speed at which it sails off the bat are all important factors. The Sweet Science. The force of the swing is also a key factor in the performance of a baseball bat, as a hard swing can generate more power, while a softer swing can produce more control. The shapes of the force vs time curves are interesting since they tell us how the force on the ball varies with the amount of compression. This website uses cookies to improve your experience while you navigate through the website. The sweet spot of a bat exists because bat vibrations are not excited significantly at that spot. Impact at the end of the bat (outside the sweetspot) causes the bat to vibrate violently after the collision. The illumination of the ordinaryof why the sky is blue or why the stars shineis not the least important role of physics and physicists. << To squarely hit a fastball, everything has to . The result was not a super slow softball spin, neither was it particularly fast. Wood bats hit farther than metal bats, which is the clear distinction between them. >> >> An impact at the fundamental node will not excite that mode, but it will excite the second mode. Maple bats are the most durable and have a larger sweet spot, making them ideal for power hitters. The sweet spot of a bat exists because bat vibrations are not excited significantly at that spot. Mass has no effect on distance, but if you cant generate enough bat speed to overcome mass, you are doing yourself no favors and going backwards. >> It has been found that the swing speed for any given batter is proportional to 1/(Swing weight)^n where n is typically about 0.27 for most batters. Other research indicates that the 'sweet spot' lies between the nodes of the lowest 2 vibrations of the bat. If the bat is at rest then we can define the ball speed ratio, Bounce Factor = q = (ball exit speed) / (incident ball speed).