The physics behind this phenomenon involves the transfer of energy from the bat to the ball. 9-d\DA=cZ0Q>gIM$$;cd2O@&a;X,Nn_aP(]I1aRc(K1^ue> But opting out of some of these cookies may affect your browsing experience. He received his Ph.D. in physics from the University of California, Berkeley, where he conducted research on particle physics and cosmology. When a pitch is played, a turbulent stream of air runs behind the ball. Second, we give a simplified abstract form of bat which facilitates the description and modeling study. As the ball leaves the bat, the potential energy is converted into kinetic energy. The effect is known as the "trampoline effect". Some results for an Easton BK7 aluminum bat are shown below in 13 QuickTime movie files, each about 1 Mb. 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. 13 0 obj The material of the bat can affect its performance, as lighter bats tend to be more responsive and have higher exit velocities. A great way to keep a rhythm throughout your swing is to step or stride toward the pitcher. 2. Baseball is a beloved American pastime, with millions of people playing the game recreationally or professionally each year. 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. /N 13 0 R If there is a force of 5,000lb on the ball then . First and foremost, we develop a simple but effective theoretical model to give a rough estimate for the sweet spot of the bat. The direction of the centripetal force is toward the center of the circle followed by the path of the CM. J,g]g+e/h_!_gCtO=0f)$P%cIi8Zdfc5&3j_8$7g. << Rather, most coaches and others think in terms of wrist torque, which is probably much too small to provide the necessary large couple near the end of the swing The couple must come mainly from the two arms, not the wrists. All this means that if goal of the bats design is to provide more power and speed, it makes it more likely to to crack and shatter. Baseball bats (typically aluminum) are made up of either hardwood or metal. >> @L`YKUJNGBP\poR=_;Dl'P(T >> gF/(+GaKo$qneLWDrQ#;5\S(\$q'LM9bYJX9N;hHO_e;>`Y"/'J:I~> 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. 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. The true CoP should be measured from that point. /I << Impact at the end of the bat (outside the sweetspot) causes the bat to vibrate violently after the collision. But its not that simple. A homerun hit right at the sweet spot would sound different than one hit off the target. keywords: COR(Center of percussion), sweet spot, oscillation Edited : 2020/10/11. These vibrations travel in waves up and down the length of the object. 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. Since its vibrations that hurt your grip, the sweet spot is clearly the point where an impacting ball doesnt cause the bat to vibrate. forms: { The above results are more or less as expected, in that light bats can be swung faster than heavy bats. 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. This is because physics plays a major role in how the bat interacts with the ball. To understand such collisions it is important to first understand the physics of a collision between one ball and another. Sniper Skin Announces Their Newest Partnership with Bassmaster Opens Pro, Briana Tucker! Thick walls are also needed to help prevent the walls dinting or cracking. 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. Reflexes. Additionally, a hard material helps to reduce the amount of vibration that travels through the bat and into the players hands, helping them to maintain control over the bat while swinging. Share your thoughts with us below! Largest thickness - The sweet spot Bat - Ball Collision Diagrams Vball 1 = Vb Vbat 1 = V2b V bat 2 = V2a Vball = V1a Before After the location where coefficient of restitution is maximum. Wood bats hit farther than metal bats, which is the clear distinction between them. 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. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We use the idea that if a body collides with something, then its angular momentum is conserved with respect to the point of impact. Hitting on the sweet spot ensures you dont lose any more energy to making vibrations inside the bat. throughout the paper. The ideal is the 110 turn model. 1 0 obj 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. A bat is essentially a long stick. Initially, the force on the handle is in the opposite direction to the motion of the handle. 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 you hit a ball just right, you've hit it on one of the three "sweet spots" of the bat. The bat barrel initially bends backwards away from the ball while the handle bends outward and the vibration in the handle causes the players top hand to lose contact with the handle. << 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 bat approaches a ball incident at speed vin then. 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. The answer depends on how fast each bat can be swung. /R [316 73 572 791 ] 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. Players tend to feel a zing in their hands; often called bat sting. Swinging a Bat.- 7. There is no simple physics answer to the heavy/light bat question here. What are the physics of hitting a baseball? The result was not a super slow softball spin, neither was it particularly fast. 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. These cookies ensure basic functionalities and security features of the website, anonymously. Adair provides a few answers in his book The Physics of Baseball but he does not give the directions or the torques. 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. In bats made of maple wood, like the Axe Bat, it's easy to find the strongest grain. In theory, the ball bounces best for an impact at the center of mass of the bat, provided we can ignore bat vibrations. 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. How is this spot and its behavior described in Mechanics? The tube wall is thinnest, stretchiest, and tapered before being rolled, and then the handle is formed. Then can't we add to the list of deeper queries some of . This makes the game easier to pick up and more exciting to watch otherwise, every hit would only be a single. Explains r. cross, "the sweet spot of a baseball bat," american journal of physics, 66, 772-779. A good power hitters bat is an end-loaded one, which allows the player to hit the ball farther. See, the trouble with wood is that it vibrates. Thank you so much for. endobj If the bat approaches a ball incident at speed v. Are heavy bats are more powerful than light bats? Step up to the batters box and get warmed up for the physics of baseball bats with this, You can get into the real nitty gritty of the science of MOI including complex equations by clicking through to the complete, 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. There is a greater amount of strength required to swing a wood bat, but the ball exits faster when hit. What is the biggest problem with wind turbines? The batter might find that he needs to change the way he swings the bat if the swing weight is altered, or he might have a grooved swing technique and swing every bat the same way. Where on the bat is the ball struck with the greatest speed? You also have the option to opt-out of these cookies. This is the location of the bat that is generally regarded as the best spot for hitting the ball. The bounce factor found from these and some additional impacts is shown below. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. , 231-232 (2001). not apply to baseball or softball bats. Continue with Recommended Cookies, Copyright 2009-2023 real-world-physics-problems.com. External forces are the only way to redirect the ball according to the first law of motion. The experiment described below would be an ideal project on the physics of baseball, for any high school or University physics student. Batters know from experience that there is a sweet spot on the bat, about 17 cm from the end of the barrel, where the shock of the impact, felt by the hands, is reduced to such an extent that the batter is almost unaware of the collision. What happens to the dry ice at room pressure and temperature? Are you a fan of composite or wood? the location which produces maximum batted ball speed. Results for a baseball dropped from heights of 1, 5, 10 and 15 cm onto a piezo are shown below. Basic Physics.- 2. This is similarly done for tennis rackets and baseball bats. Different materials have different natural vibrational frequencies, and depending on how large or small the waves are, there are nodes at evenly spaced intervals along any object where it wont vibrate at all if struck. Lighter bats, on the other hand, are better suited for contact hitters who are looking to make contact with the ball and generate less power. /V 15 0 R The hand moves forward faster than this in practice, so the spin rate could easily be around 1500 rpm. The impact on a baseball bat is shorter (since the bat and ball are harder or stiffer), about 1 msec. If there was no loss of energy during the bounce then COR would be 1.0. It was there that he first had the idea to create a resource for physics enthusiasts of all levels to learn about and discuss the latest developments in the field. /R [52 73 308 791 ] Newton's third law says that for every action there is an equal and opposite reaction. The direction of the centripetal force is toward the center of the circle followed by the path of the CM. Sign up to receive Popular Science's emails and get the highlights. Baseball is based on the principles of Newtons laws of motion. The majority of wooden bats are made from ash, with maple, hickory, and bamboo following in their footsteps. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". Boxing. It's where the wood grain is strongest. Bats and Balls.- 3. Some of our partners may process your data as a part of their legitimate business interest without asking for consent. 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. The outgoing speed of the ball is just the sum of the two separate parts - the speed when the bat is at rest plus the speed when the ball is at rest. The tubes were suspended by a length of string so that they could vibrate for a long time without damping. Joe Jackson, a shoeless man, would prefer a custom-built bat known as Black Betsy. Wind farms have different impacts on the environment compared to conventional power plants, but similar concerns exist over both the noise produced by the turbine blades and the . The bat is 84 cm long, and has a mass of 849 gram. It is not quantum physics or relativity, but a very interesting problem involving the mechanics of colliding objects. 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. The physics behind this phenomenon involves the transfer of energy from the bat to the ball. We and our partners use cookies to Store and/or access information on a device. If the ball is also mounted as a pendulum. When a player has a bad hit and fails to hit the sweet spot, it causes vibrations which can cause the bat to bend or break. The player will swing the bat from low to high, with too much bat speed resulting in fly balls. /Length 996 A high performance bat has a strong trampoline effect and hence a relatively large COR. [/CalRGB Typical results are shown here for a superball, a baseball and a sorbothane ball. /N 21 0 R How is this described in Mechanics? 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. In file A, the ball spins faster than in file B, both before and after the bounce. There are some models that include oak, but it is not as popular as maple or ash. In fact, if the ball strikes the bat exactly on the ``sweet spot'' then the hitter is almost unaware of the collision. The majority of hitters take a stride when hitting, which helps the timing of their swing. 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 . produce and innovate modern day cricket bats. Upon impact with the ball, the rotation of the bat is reversed. Subscribe to get special offers, free giveaways, and once-in-a-lifetime deals. (function() { Taking the rotation rate as 3/8 revolution / 0.04 sec gives 9.4 revolutions / sec or 560 rpm. Hey, were not all headed to the majors. The higher the number, the heavier the bat will be, meaning it will have more mass and therefore more power when it makes contact with the ball. << Is swinging a bat potential or kinetic energy? It minimizes vibration of the bat and results in the maximum energy delivered to the ball, meaning it travels the farthest. Choosing the right wood is essential for the proper performance of baseball bats. This website uses cookies to improve your experience while you navigate through the website. /R [52 73 308 791 ] The heavier the bat, the higher the bats bat speed. << As a result, the fundamental and second vibration modes are both excited with about the same amplitude. /P 14 0 R 1) Hit with the label up Manufacturers always place the label on the face of the grain. /Gamma [1.8 1.8 1.8] On average, players aged 15 to 17 hit 140 feet, while players aged 16 to 18 hit 150 feet, and players aged 18 to 19 hit 165 feet. 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. Otherwise, the effective mass of the bat is less than its whole mass. /P 14 0 R Where is the best place on a bat to hit the ball? Ball Trajectories.- 4. 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. It was found, by measuring the frequencies of lots of aluminum tubes (see photo). 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. READ SOMETHING ELSE Table of Contentsshow A ball that strikes the bat does not cause it to vibrate at this point. The wood bat is ultimately the best choice for any player who wishes to use a bat with the most natural power and the fastest speed. This equation for acceleration can , Dry ice is the name for carbon dioxide in its solid state. /N 15 0 R Last . Each baseball bat has a sweet spot due to vibrational physics. /V 24 0 R As a smaller player, you will generally be able to achieve faster bat speeds with a lighter bat. Ball Hysteresis.- 10. In file A, the tangential COR was surprisingly high, about 0.3. It does not store any personal data. { Why does hitting a baseball on the sweet spot of a bat result in a better hit than other parts of the bat? 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. /V 9 0 R The first is where the bat feels best in your hands when you hit. Near the end of the swing, the force is roughly at right angles to motion of the handle since the centripetal force is very large. When you hit the sweet spot, the bat feels the best in your hand. Strike at 12 cm Strike at 17 cm Strike at 24 cm Strike at 31 cm. Learn how the sweet spot correlates with movement and vibration. Metal bats, on the other hand, are lighter and more forgiving, but they lack the power of iron bats. The following three movies show a batter swinging three different bats as fast as possible, filmed at 25 frames/sec. 9 0 obj << 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. When a batter hits a ball, the bat will rebound from the force of the collision. /WhitePoint [0.9505 1 1.089] >> 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. Two ounces doesnt seem like much but Ive seen it make a large difference. For example, a 33-inch bat with a -3 rating weighs 30 ounces. Wood bats and aluminum bats have their own set of advantages and disadvantages, and the choice for the player is based on preference. >> stream A bat with an end loaded weight indicates that it weighs between 30 and 28 ounces. Not hitting the ball with the sweet spot of the bat causes more vibrations, which causes the sting for the batter. . That is, a large fraction of the stored elastic energy in the wall is retained as vibrational energy in the bat. According to Science Daily, human hands are sensitive to vibration frequencies between 200-700 hertz and we experience the most pain when those frequencies are between 600-700 hertz. I simply wanted to know whether a hand launched ball spins at around 100 rpm or whether it could be as high as 1000 rpm. With each hit, you should hear and feel the vibrations (make it easier by taping a paper cone around the knob, loosely enough that it will vibrate when the bat does). So, why does the MLB still use wooden bats? However. By maintaining the same swing speed with a heavier bat, players can increase bat speed and distance in the same manner. 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. } And though the term is almost always used exclusively to talk about baseball, the scientific principles that explain the sweet spot are actually true of tennis rackets, hockey sticks, and cricket bats as well. It would therefore not be surprising if a softball can be pitched at say 1000 rpm. 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. 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. The cookies is used to store the user consent for the cookies in the category "Necessary". You can test your childs grip by having him or her hold the bat straight out in front of them, parallel to the ground, with their dominant hand. /V 16 0 R 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. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. Newtons second law, which deals with the value of time, is also important in baseball.