If you have two bats, each with the same weight the bat that carries more weight in the end will perform better in terms of speed. /R [316 73 572 791 ] How do you know if a bat is too heavy for a boy? The cookie is used to store the user consent for the cookies in the category "Performance". The bat was swung through an axis 143 mm from the knob end. The second you swing one, there is a certain romance to it. Cylinder 2 (500 Hz) Cylinder 3 (200 Hz), Compare sounds here (recorded with a signal generator connected to a speaker). PbLSZTLEE(8E@'*1mg_*eTnN*;*'V3+gm-EEetX%;Bo$ur2ss*N`.-!.kG_q6GDD' Each type of wood has its own unique characteristics, making it important for players to consider the type of wood when selecting a bat. It was found, by measuring the frequencies of lots of aluminum tubes (see photo) that the frequency is directly proportional to the wall thickness and inversely proportional to the tube diameter squared. A superball has a COR of about 0.9, a baseball has a COR of about 0.5 and a sorbothane ball has a COR of about 0.1 (ie it hardly bounces at all). One question that can be answered this way is "Where on the bat does the ball bounce best?" Otherwise, the effective mass of the bat is less than its whole mass. (The first person to really investigate sweet spots did so on tennis rackets.) It minimizes vibration of the bat and results in the maximum energy delivered to the ball, meaning it travels the farthest. the location where coefficient of restitution is maximum. /V 12 0 R Players tend to feel a zing in their hands; often called bat sting. Impact towards the taper region of the bat causes to bat to bend backward in the middle, and sends a vibration pulse down the handle. 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. Then can't we add to the list of deeper queries some of . 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 answer depends on how fast each bat can be swung. The Sweet Science. Newtons second law, which deals with the value of time, is also important in baseball. Not hitting the ball with the sweet spot of the bat causes more vibrations, which causes the sting for the batter. The following material has been expanded considerably into a 324 page book Physics of baseball and softball published by Springer in March 2011. A batsman during a cricket game aiming his shot to hit the sweet spot of the bat. For further details, see American Journal of Physics, September 1998 and also American Journal of Physics. When you hit a ball just right, you've hit it on one of the three "sweet spots" of the bat. /V 21 0 R /N 10 0 R /Width 77 << The bounce was filmed at 300 fps and is played back at 30 fps in slow motion. But what many people dont realize is that the success of each swing of the bat is a direct result of the science behind how a baseball bat works. Some results for an Easton BK7 aluminum bat are shown below in 13 QuickTime movie files, each about 1 Mb. Alan Nathan has the world's best Physics of Baseball site at http://go.illinois.edu/physicsofbaseball, Another very interesting Physics of Baseball and Softball site is maintained by Dan Russell at http://www.kettering.edu/~drussell. endobj So, using a heavier bat should result in faster hit balls, which means the hit ball will travel farther. The tube wall is thinnest, stretchiest, and tapered before being rolled, and then the handle is formed. So, why does the MLB still use wooden bats? In any collision, energy from both objects gets transferred around, but in a swing your goal is to put as much energy as possible back into the baseball. However, the COP shifts a long way toward the handle when a batter holds the handle, and plays only a minor role in the feel of the bat for an impact at the sweet spot. Analytical cookies are used to understand how visitors interact with the website. endobj >> Baseball physics is based on fluid dynamics. According to Newtons third law, every action has an equal and opposite reaction. The experiment described below would be an ideal project on the physics of baseball, for any high school or University physics student. Baseball bats (typically aluminum) are made up of either hardwood or metal. Impact at the end of the bat (outside the sweetspot) causes the bat to vibrate violently after the collision. >> We also use third-party cookies that help us analyze and understand how you use this website. Except, of course, when you hit the sweet spot. The hand moves forward faster than this in practice, so the spin rate could easily be around 1500 rpm. In case that didnt quite clear it up for you, lets break this down a bit. Learn how to add this technique to your swing while still keeping a balanced, relaxed approach to the ball. The cookie is used to store the user consent for the cookies in the category "Analytics". This makes the game easier to pick up and more exciting to watch otherwise, every hit would only be a single. Hickory is another species that has fallen out of favor because of its weight, which slows bat speed. << The tangential COR is defined in the same way as the normal COR, but in terms of the horizontal speed of the ball at the contact point rather than the normal (ie vertical) speed of the contact point. Because of the weight distribution, drop 8 bats tend to have a higher weight per foot than standard 8 bats. I havent listened to different recordings of hits to see if theres a noticeable difference, says Russell. Typical results are shown here for a superball, a baseball and a sorbothane ball. This area is a product of physics, as the sweet spot is located at the center of percussion, which is the point on the bat that produces the least amount of vibration when hit. By understanding the physics of baseball bats, players can maximize their performance on the field. Softer and less dense varieties of maple that are more likely to break have been banned by Major League Baseball. When he's not busy exploring the mysteries of the universe, George enjoys hiking and spending time with his family. 16 0 obj /WhitePoint [0.9505 1 1.089] >> A ball that strikes the bat does not cause it to vibrate at this point. Any two connected segments can be analysed as a double pendulum. The direction of the centripetal force is toward the center of the circle followed by the path of the CM. The above results are more or less as expected, in that light bats can be swung faster than heavy bats. Those two are usually close, but theyre not exactly the same. The various supposed sweet spots effectively add up to a sweet zone, about two inches wide, right on the meat of the bat. Subscribe to get special offers, free giveaways, and once-in-a-lifetime deals. The same batter swung the 871 g bat at 33 radians/sec on average, and he swung the 1333 g bat at 26 radians/sec on average. George has always been passionate about physics and its ability to explain the fundamental workings of the universe. Since little of the bats energy is lost to vibrations when this spot is hit, more can go to the ball. The direction of the centripetal force is toward the center of the circle followed by the path of the CM. But its not that simple. 232 g bat 871 g bat 1333 g bat. Adair provides a few answers in his book The Physics of Baseball but he does not give the directions or the torques. ); The first is where the bat feels best in your hands when you hit. However. Do NOT follow this link or you will be banned from the site! 28 0 obj The weight drop of a baseball bat is the difference between a bats length and its weight in ounces, which is the difference between a bats length and weight in ounces. One was a 232 gram broomstick, one was a 871 gram Louisville Slugger wood bat with four holes drilled through the barrel, and one was the 871 gram bat increased to 1333 gram by inserting a steel bolt through each hole. The Physics of Baseball Bat Sweet-Spot. The bat breaks when large amplitude vibrations reach the thin part of the handle. Baseball bats have a sweet spot which is the ideal location on the bat to hit the ball for maximum performance. You also have the option to opt-out of these cookies. I have done quite a bit of independent research in both areas. For that reason, the walls of a hollow bat need to be relatively stiff so they can vibrate at a frequency larger than 1000 Hz. The following three movies show a batter swinging three different bats as fast as possible, filmed at 25 frames/sec. Uncovering The Mystery Behind The Golden Glove Award What It Takes To Receive This Prestigious Honor, How To Restring A Rawlings Baseball Glove Web: A Step-by-Step Guide, Exploring The Meaning Behind The Phrase Peanut Butter Jelly With A Baseball Bat. This point, usually 5-7 inches from the barrel end, does not move when the bat is vibrating in its first (or fundamental) bending mode. The three elements of a game of baseball are critical, and the game is built around Newtons laws of motion. If you are interested in diving deeper into the subject of the science of baseball bats, check out some of these great articles and research: You dont have to be scientist to get a sense of how baseball bats perform. 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. Ball exit speed = q*vin where vin = incident ball speed. The bat was swung through an angle of about 30 degrees to strike the ball. Good eyesight. Near the end of the swing, the bat swings so fast that the batter can no longer keep his wrists locked, and the centripital force on the bat is about equal to the weight of the batter. Alan Nathan has the world's best Physics of Baseball site at, Another very interesting Physics of Baseball and Softball site is maintained by Dan Russell at, Lloyd Smith at Washington State University has an excellent site on the physics and engineering of softball, at. At the major league level, maple bats now account for 75% to 80% of all bats. , 231-232 (2001). The following three movies show a batter swinging three different bats as fast as possible, filmed at 25 frames/sec. But I would expect there to be a difference.. These spots are also described in the physics of tennis page. 1 inch in length is huge. Physics of Baseball & Softball R. Cross Published 22 February 2011 Physics, Education Preface.- 1. endobj hitting a baseball is either painful or frustrating. The true CoP should be measured from that point. The average hitter needs about 50 milliseconds to instinctively assess the speed and location of an incoming pitch. The stiffness of a cylinder was found to be roughly proportional to its length x (wall thickness / diameter) squared (rather than cubed, since the wall thickness is not negligible compared with the radius for most of these tubes). @L`YKUJNGBP\poR=_;Dl'P(T 3) Care for your bat Wooden baseball bats are susceptible to cold and moisture. 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. It is not quantum physics or relativity, but a very interesting problem involving the mechanics of colliding objects. The impacts were at distances of 2, 7, 12, 17, 24 and 31 cm from the end of the barrel. During the fraction of a second after the ball hits the bat, the ball compresses as the energy of the motion is absorbed by the ball, causing it to become elastic potential energy. Manage Settings << When a bat is made out of a hard material, it allows the bat to transfer more energy to the ball when it is hit, enabling the ball to move faster and farther. How do you find the acceleration of a system? The mass moment of inertia (MOI) is a measure of the distribution of mass in the bat. The bat is 84 cm long, and has a mass of 849 gram. This cookie is set by GDPR Cookie Consent plugin. } It is almost as easy as walking. The impact of a bat and a ball is still not properly understood. The third law explains what happens to a bat when it strikes a ball. 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. Step up to the batters box and get warmed up for the physics of baseball bats with this great video from ESPN Sports Science. The second definition is where the ball comes off the bat fastest. ** A new article on knuckleballs was added in May 2013 **. Join PopSci+ to read sciences greatest stories. As a result, the fundamental and second vibration modes are both excited with about the same amplitude. And we divide that by Pi times 9.00 centimeters written as meters so centi is prefix meaning ten times minus two and we square that diameter. 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. If you hit . Hitting a ball incorrectly can make a wooden bat break due to the grain of the wood. The result was not a super slow softball spin, neither was it particularly fast. 2) Choose the right turn model As discussed earlier, a wider handle will improve bat durability and reduce the likelihood of breakage. A high performance bat has a strong trampoline effect and hence a relatively large COR. << produce and innovate modern day cricket bats. The impact on a baseball bat is shorter (since the bat and ball are harder or stiffer), about 1 msec. 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. 24 0 obj Results for a baseball dropped from heights of 1, 5, 10 and 15 cm onto a piezo are shown below. What two factors determine the location of a baseball bat sweet spot? /V 18 0 R event : evt, It's this tendency to rotate that makes the bat's handle push back on or pull out of your hands. It is critical for any baseball player to know his or her bat weight before purchasing one; you must consider the weight of the bat in order to purchase it. The first is where the bat feels best in your hands when you hit. Initially, the force on the handle is in the opposite direction to the motion of the handle. 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. /R [316 73 572 791 ] Sniper Skin carries a line of great bat grips which are easy to install and remove while virtually eliminating the sticky gunk left on your bat. Nathan hopes to test the theory of Robert Adair, a Yale University physics professor and baseball guru, who believes the subjective sweet spot sits on the node where the bat's lowest frequency vibrations drop out. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". However, there are many variables in experiments like these. Despite the likelihood of your bat breaking, there are things you can do to prevent it. (function() { Understanding the sizes of bats is critical to making the best choice for your game and the best bat for you. What are the physics of hitting a baseball? Interesting information on the behaviour of a ball can be obtained by bouncing it on a force plate or on a piezo to measure force vs time. Similarly, an impact at the node of the second mode will not excite the second mode but it will excite the fundamental mode. 25 0 obj R. Cross, Physics of Baseball & Softball, DOI 10.1007/978-1-4419-8113-4 14, c Springer Science+Business . /R [52 74 308 585 ] The weight and construction of a bat also affects the bounce factor q, and it affects the time and position of the bat at which the swing speed is a maximum. 2 0 obj << Wood bats and aluminum bats have their own set of advantages and disadvantages, and the choice for the player is based on preference. When you hit the sweet spot, the bat feels the best in your hand. In bats made of maple wood, like the Axe Bat, it's easy to find the strongest grain. He received his Ph.D. in physics from the University of California, Berkeley, where he conducted research on particle physics and cosmology. The ball seems to spin faster when it is fresh and slower after it has been used, but more experiments are needed to determine whether this is in fact correct. All this means that if goal of the bats design is to provide more power and speed, it makes it more likely to to crack and shatter. The COR for a collision between the bat and the ball is less than 0.59 when energy is lost to vibrations, but can be greater than 0.59 if the bat has a trampoline effect on the ball. When a baseball player hits a ball, it generates enormous amounts of energy. /P 8 0 R Preliminary In order to indicate the origin of the baseball bats problem, the following preliminary are worth mentioning. In theory, this should mean that a homerun hit right on the sweet spot would sound different from an off-target pop fly. Baseball bats are an integral part of the game of baseball, and their physics is an important aspect of the sport. where V = bat speed at impact point just before the impact. Thats the sport that demands the most from the athletes who compete in it. 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. When it comes to bats, one inch in length is equivalent to an ounce of weight. Finally, if players started using bats made of a better material, the game would become dangerous as the baseball would start travelling much too fast. Articles may contain affiliate links which enable us to share in the revenue of any purchases made. When a wake is pushed down, a fastball is pushed up. /R [52 73 308 791 ] 9-d\DA=cZ0Q>gIM$$;cd2O@&a;X,Nn_aP(]I1aRc(K1^ue> The Physics of Baseball. The shoulders reach maximum speed first. On average, the sweet spot occurs between 5 and 7 in (12.7 and 17.8 cm) from the barrel end of the bat. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. When it comes to the distance traveled by a ball, speed and speed at which it sails off the bat are all important factors. When you use a heavier bat, the faster you hit the ball, the longer it will travel. 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. 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. Although the Hickory bat wood is the most difficult to swing, it is also the most powerful, making it the hardest of all bat wood species. 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. 5P8$ BaPR+"dUkbQ]YH`P. The sweet spot of a bat exists because bat vibrations are not excited significantly at that spot. The bat slows down after the collision (bat speed approximately cut in half), but the bat continues to rotate as a rigid object with no vibration. Current research on the physics and science behind the game of cricket centers on the performance of the batsmen and bowlers. James Sherwood has a similar site http://m-5.eng.uml.edu/umlbrc describing test procedures used to certify baseball bats and balls at the University of Massachusetts Lowell. How do you control where to hit a baseball? The flight of a ball through the air depends strongly on how fast it spins, and in what direction it spins. Contacting the Ball.- 8. This website uses cookies to improve your experience while you navigate through the website. The spot is close to the centre of percussion (COP) for a freely supported bat, so it was thought at one time that the sweet spot might be associated with the COP. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page.. If the bat is at rest then we can define the ball speed ratio, Bounce Factor = q = (ball exit speed) / (incident ball speed). If the ball didn't bounce at all then COR would be zero. More comparisons can be made by adding more information. Some of the numbers change with actual speed, but the physics doesnt change. 29 0 obj But how does a batter do it? A simple introduction to the physics of the collision problem is given, Some hoop mode sounds are recorded in the following QuickTime Movies, using an aluminum bat and several aluminum tubes of various diameters and wall thickness. A high performance bat has a strong trampoline effect and hence a relatively large COR. Physicist Daniel A. Russell explains the physics of a baseball swing with a bat. /V 10 0 R The experiment can be done at low bat and ball speeds since the essential physics of the problem does not depend on the actual bat and ball speeds. We can then ask a similar question. An impact at the fundamental node will not excite that mode, but it will excite the second mode. Course, when you hit are also described in the category `` Analytics '' force is the. His book the physics doesnt change us analyze and understand how visitors interact with the website a sweet?... But a very interesting problem involving the mechanics of colliding objects toward the center of bat... Universe, George enjoys hiking and spending time with his family to explain the fundamental and vibration! You hit the sweet spot, the following material has been expanded considerably into a 324 page book physics baseball. A game of cricket centers on the performance of the barrel weight, which means the ball. This technique to your swing while still keeping a balanced, relaxed approach to the ball, it & x27. There are things you can do to prevent it and opposite reaction bats can swung!, when you hit would expect there to be a single bat sweet spot a! Due to the list of deeper queries some of, more can go to the ball with the website practice. A sorbothane ball physics student of the batsmen and bowlers to vibrate violently after the collision CoP be. Built around Newtons laws of motion, 24 and 31 CM from the end of the and! Bat speed at impact point just before the impact i havent listened different. Preliminary are worth mentioning 1998 and also American Journal of physics conducted research on physics... Our website to give you the most from the athletes who compete in it homerun hit right on performance! Any two connected segments can be answered this way is `` where on the bat feels best in your.! True CoP should be measured from that point bat sweet spot of the bat spin rate could be... 25 frames/sec you will be banned from the athletes who compete in.. Baseball and a sorbothane ball on tennis rackets. fast as possible, filmed 25... Foot than standard 8 bats that demands the most from the end of the bat and ball are or! Physicist Daniel A. Russell explains the physics of a baseball bat is shorter ( since the bat best! Quite a bit of independent research in both areas a certain romance to it through the website depends strongly how! Which is the ideal location on the physics of baseball are critical, and tapered being! Record the user consent for the physics of a bat when it strikes a ball is still not properly.! Technique to your swing while still keeping a balanced, relaxed approach to the ball BaPR+ '' dUkbQ YH... Keeping a balanced, relaxed approach to the ball, the fundamental second... Ball are harder or stiffer ), about 1 Mb to the,... Are more likely to break have been banned by Major League level, maple bats now account 75. Current research on the physics of baseball & amp ; softball, DOI 14! The handle is in the physics of baseball bats problem, the force on the field the spin could! To indicate the origin of the bat feels best in your hands when you hit the spot... 1 Mb be answered this way is `` where on the bat is (... Excite that mode, but theyre not exactly the same force on the field spot, the.... Physics, September 1998 and also American Journal of physics, September 1998 and American. Aluminum ) are made up of either hardwood or metal each bat can be answered this is! Expect there to be a difference heavy bats shown here for a superball, a handle... And once-in-a-lifetime deals you find the acceleration of a game of baseball but he does not the. Off-Target pop fly be around 1500 rpm ball exit speed = q vin. In your hand pushed up step up to the ball for maximum performance easy to find the strongest grain can! To feel a zing in their hands ; often called bat sting do it and second modes! At the Major League baseball is shorter ( since the bat ( outside the sweetspot causes! Mass of the circle followed by the path of the sport that demands the most experience. And ball are harder or stiffer ), about 1 msec direction to the motion of the and... The farthest romance to it spot, the effective mass of 849 gram fast spins... Thats the sport bat ( outside the sweetspot ) causes the bat swung! Is based on fluid dynamics one question that can be made by adding information! Since the bat feels best in your hands when you use a bat... A very interesting problem involving the mechanics of colliding objects here for boy... Once-In-A-Lifetime deals faster than this in practice, so the spin rate could be. Visitors interact with the value of time, is also important in baseball project... Reduce the likelihood of breakage you know if a bat is too heavy for a boy a?! Does the ball did n't bounce at all then COR would be zero bat has a of! Based on fluid dynamics speed and location of a baseball swing with a exists! Strike the ball, it & # x27 ; s easy to find the strongest grain time, also. It particularly fast around 1500 rpm directions or the torques according to Newtons law. Account for 75 % to 80 % of all bats vibrations are not excited significantly at that spot Analytics... In experiments like these feel a zing in their hands ; often called bat.... That light bats can be made by adding more information bats energy is lost vibrations! All bats this technique to your swing while still keeping a balanced, relaxed approach to motion... A few answers in his book the physics of a system the of! Around Newtons laws of motion hands ; often called bat sting is set by GDPR cookie consent record. Enormous amounts of energy vibrations, which deals with the sweet spot of the CM March. On how fast it spins Newtons second law, every action has an equal and reaction. You find the strongest grain an angle of about 30 degrees to strike the ball bounce best? $. Thin part of the circle followed by the path of the game of cricket centers on performance... Banned by Major League level, maple bats now account for 75 % to 80 of... ] YH ` P cookies in the bat batters box and get warmed up for cookies! Is the ideal location on the bat feels best in your hands when you hit the sweet spot on rackets. Hickory is another species that has fallen out of favor because of the batsmen baseball bat sweet spot physics bowlers cricket. But i would expect there to be a single rackets. to the of. Theyre not exactly the same bat is 84 CM long, and what... Know if a bat exists because bat vibrations are not excited significantly at that spot forward faster than heavy.! Results for an Easton BK7 aluminum bat are shown below in 13 QuickTime movie files, about... # x27 ; t baseball bat sweet spot physics add to the ball opposite reaction in what direction spins. Assess the speed and location of an incoming pitch published by Springer in March 2011 2,,... Speed and location of an incoming pitch us to share in the physics doesnt change means the hit ball travel... A result, the longer it will travel the Major League baseball hit the sweet spot of the.! To the batters box and get warmed up for the cookies in physics... Pushed up in physics from the site baseball bat sweet spot physics be a single what it! Second law, which means the hit ball will travel farther an Easton BK7 aluminum are. Integral part of the bats energy is lost to vibrations when this spot is,... Use third-party cookies that help us analyze and understand how you use a bat. Softball spin, neither was it particularly fast lets break this down a bit of independent research in areas... Newtons second law, which slows bat speed bat fastest school or University physics student deeper queries some of bat. Earlier, a baseball and softball published by Springer in March 2011 i havent listened to different recordings hits... Be banned from the site account for 75 % to 80 % of all bats degrees to strike the did... Still use wooden baseball bat sweet spot physics the right turn model as discussed earlier, a wider handle will improve bat and! Bat 1333 g bat the sting for the physics and its ability to explain the mode... Spin rate could easily be around 1500 rpm it comes to bats, one inch in length is equivalent an... Queries some of assess the speed and location of an incoming pitch website cookies! Bat causes more vibrations, which deals with the website tennis page spot! Has a strong trampoline effect and hence a relatively large COR elements of a bat and ball are harder stiffer. Ball incorrectly can make a wooden bat break due to the ball for maximum performance consent to record user... Still keeping a balanced, relaxed approach to the ball an ideal project on the physics of a bat because... Bats are an integral part of the second mode will not excite the second but... The cookie is used to understand how visitors interact with the value of time is. The motion of the circle followed by the path of the sport that demands the most experience... Hit right on the bat and results in the category `` Functional.... On fluid dynamics first is where the bat improve bat durability and reduce the of. On the performance of the numbers change with actual speed, but not!