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## The Physics of Moving On :(

Well its been real Physics C.  Here I am, sitting here, writing my last blog post of high school (and maybe forever).  This class has been a huge undertaking, but also something that I am glad I attempted.  Although the work has been hard and I am far from even coming close to mastering some of these complex concepts, my time with Physics has been amazing and enlightening.  It has opened me up to a totally new way of seeing things, and I cant wait until I can put what I've learned into use while I study to become an Architect.  Without a doubt I will be taking Physics in College, but anything past mechanics I can just leave to the engineers (hey Skylor and Justin ;))  With that said, I know the knowledge I have gained in all aspects of Physics will forever help me through all professional (and maybe some personal) challenges.

I just hope and pray that whatever physics god may be out there will here these last few simple requests:

1.  May the downward force of all of my dorm supplies be much less than the maximum possible opposing force of that ratty box I dug out of my garage.

2.  Also, when all that crap does come falling out of the bottom of the box,  please make sure I'm not halfway up the stairs in front of a group of upperclassmen.

3. And if both of those things do end up happening, please oh please make sure the friction provided by that shirt that got under my feet from the box is enough to keep my feet static on the step.

4. And lastly, please keep any torque on my UCL below 70 ft-lbs - that would be great.

But for real, I am so excited to see what the rest of this year of physics has in store for me and for the adventures that are bound to follow.

## Baseball Bats Part 2

Today we were hitting in the field house as part of our practice and I decided to focus on something I always knew happened, but never knew why.  Every time a baseball bat rolls, it always does so in a circular fashion.  This can be really annoying especially when it gets set down and then all of the sudden it starts randomly rolling off in a circle and depending on speed, always goes in a different path.  The more I thought about it, the more I was amazed that it could be explained simply with physics.  The bat is essentially a long rod with two ends of different diameters, and therefore, circumferences.  Because there is no part of a bat that allows the top and bottom to rotate independently, the two different ends must rotate at the exact same angular velocity.  But because they are different sizes, one rotation of one end will cover more ground than the single rotation of the other end.  For an example, think of a bat with one end of the bat with a circumference of 5 cm and the other end with a circumference of 2 cm.  If the whole bat is rolled along the ground so the ends spin at 1 revolution per second, that means the top of the bat is covering 5 cm every second, and the bottom is covering 2 cm every second.  This change in distance traveled forces the bat to rotate lengthwise to accommodate for the difference because as we said before, neither end can speed up or slow down to even out the displacement of the unequal ends.  Through a little physics, I was able to explain something that every baseball player has thought about at least once.  And now I get to explain it to everyone on my team and watch them pretend like they care (even though this is really some cool stuff.)

## The Physics of "What If".....

The past few days in Physics, a lot of people have been talking about space, time, dimension and how all three of those things are very fluid in reality.  Since the tiny lecture we had on it last week, I have been thinking about the endless possibilities that could arise if these notions become more widely accepted and studied. One thing that really got me interested was the theory of alternate realities.  The simple fact that there are endless universes, every one playing out every single possibility of every decision you ever made.  For each one of these realities, if they do exist, there must be some sort of physics guiding the objects of that universe and whether they would be like ours or completely different, who knows.  Also, if there are proven to be multiple universes, how may we use physics to interact with, or even influence a parallel universe?  The last big question I had was: what would other realities of our world look like if some of the smartest men in our history interpreted the world in a different way, or didn't make the same groundbreaking discoveries.  Would we have the technology we have today? Or would it be something more serious, like the total change of the very Physics principals we study currently.  To me, these are very thought provoking questions that I hope you may enjoy thinking about, and maybe even answering.  Who knows, maybe one day we will live to see these very questions answered by the brightest minds of our time.  And how will those discoveries impact our reality?

## The Physics of a Broken Spoon

In spite of the title above, this blog post will NOT be about the unfortunate event in which your trusty spoon just cannot take the weight of all that cereal.  This is going to be about my unfortunate brother, Chad, who is affectionately known as Spoonhead (or Spoon for short) due to the fact that his small head bears an uncanny resemblance to that of a spoon.  Last night, Chad started in his 22nd Varsity baseball game (hes a sophomore) but only lasted about 3 innings because he went down with an ankle injury running to first on a routine ground ball.  Around 10:00 last night, we found out he broke both his tibia and fibula (both leg bones) right above his ankle.  Although the injury was gruesome, the way it happened is interesting when analyzed from a physics perspective.

At the moment the injury occurred, Chad's foot was impacting the bag at a velocity vector which was not perpendicular to the face of the base.  (That is a big no-no if you want to avoid injury crossing the base).  When the foot impacted the base, the force that the base exerted on the foot made it roll over itself as Chad's momentum from his body weight propelled his legs forward even after he stopped using his muscles to voluntarily move his legs.  This rotation of the ankle created a torque that was way too much for his lower leg/ ankle to handle and caused both bones to snap suddenly.  Thankfully, it was a quick, clean break and no surgery was required.

Get well bro.

## HBP

HBP- Hit By Pitch is a common abbreviation seen in every stat line in baseball.  It is something that looks a lot less painful than it actually is- especially in the majors when some guys just shrug off 90+ mph fastballs.  One interesting thing about getting hit by a pitch (which I have some good experience with) is the fact that there really is a wide range of pain associated with the event.  There are many factors that effect the pain factor for the batter.  Things such as location, pitch type, velocity (obviously) and most importantly, flight of the ball after contact, dictate how bad the experience is for the batter.  Since I was young, and before I knew a lot about physics, I inherently knew to cringe every time a guy got nailed and the ball just dropped at his feet instead of whizzing by because of a deflection.  Now it makes more sense... using simply the equation for momentum, one can see why HBPs that stop the pitch are more painful.  When the ball is stopped in its tracks, the body is imposing a massive impulse force on the ball, totally matching the momentum of the pitch (which trust me, there's a lot of momentum).  When the ball merely deflects off a batter and continues with some velocity past the player, the force exerted on the ball is less and therefore the force the ball exerted on the person was less.

This observation aside, there have recently been a push towards small, form fitting elbow guards worn by batters.  In a batting stance, the guard protects the elbow that is almost hanging over the plate, so in the likely event that the batter is hit there, the energy from the ball will be dissipated through the guard, and not the elbow.  Another pro of the small, form fitting guard is the fact that there is much less surface area perpendicular to the flight of the ball, which reduces direct hits, and therefore reduces the amount of force felt by the guard and elbow.

And for your viewing pleasure, here is a player charging the mound because of a fastball he caught up near the head

And if anyone needs any ideas for blog posts... I think you should go to 3:00 on this next video and analyze Jose Bautista's glasses, helmet and face as a system with Roughned Odor's fist and see if the system conserves energy.

## The Physics of Yadier Molina

A common part of baseball is seen almost every pitch when the catcher moves his glove slightly when he catches the ball to try and convince the umpire the pitch was actually a strike, when really it was a ball.  This is called framing, and when one really looks at the process, it is easy to see how strong and skilled a catcher must be to execute it.  One of the best in the game at this is Yadier Molina.  In the video below, take a look at how Molina totally redirects the tremendous force of a ball travelling over 80 mph and sinking down below the zone.  The way Molina "sticks" the pitch on the corner of the zone led to this pitch being a strike, even though it is very clear it should have been a ball.  He moves his glove up while barely moving backwards, meaning he absorbed and counteracted the downward angled force of the ball in a split second, and made it appear that he actually caught the ball at a spot above where he actually didnt.  When one thinks about the serious force behind a major league pitch, Yadier's tremendous strength becomes even more apparent, as he appears to move his glove at will, even though it is being impacted by a projectile travelling at over 80 mph.

## The Physics of Cruise Ships

Over the break, I took a 5 day cruise into the Gulf of Mexico.  Although there wasn't any internet connection for me to have Mr. Fullerton's videos grace my presence (I know what I'm going to be doing all day today), I was still thinking about physics the entire cruise.  One particular event that made me use my physics knowledge took place when we were walking down the pier in Progreso, Mexico.  Another Carnival cruise ship was leaving the port as we were about to get on our ship.  The boat backed away from the dock and once it was out in the middle of the harbor, it began to turn in place.  One thing that many don't know about large ships is the fact that they have large thrusters that exert a force perpendicular to the side of the boat, making lateral movements such as docking maneuvers much easier and safer.  Another cool use for the thrusters is turning the ship in tight areas.  There are 2 pairs of these thrusters, each pair on opposite ends of the boat and each thruster of the pair facing opposite directions.  By using the thrusters on opposite sides and ends (two thrusters that are "diagonal" to each other), the captain can turn the ship on an axis to, in this case, point the ship in the direction of the opening of the harbor.  On this particular day, there was a very strong wind blowing in from the ocean and while the boat was turning, there was no force vector produced by the thrusters that pushed the ship away from shore, so the wind was allowed to accelerate the ship back towards the pier.  After the turn was complete, the ship was traveling with a small velocity backwards.  Despite being a small velocity, the fact that a average cruise ship can weigh 60,000 tons automatically means any velocity will translate into an insane amount of momentum. This huge momentum was put on display as the main engines were fired up because even though the black smoke was pouring out of the smokestack, the boat continued to travel backwards for a few long seconds before finally the force of the engines met, and eventually overcame the momentum caused by the wind.

This application of a relatively simple concept is shown to have vital importance because without a sound knowledge of the relationships of the forces around him, the captain could have easily put the 3,000+ passenger's lives in extreme danger.  It is really cool to think about the giant forces one must harness in order to make a cruise a success.

## Back to Baseball (Why Derek Jeter's Jump-throw is so Impressive)

(49 short days until game #1)

Today was a very eventful day in the baseball world.  Spring training started and Hannah and Derek Jeter announced the birth of their first child.  To celebrate both,  I thought I would break down the physics behind two of Derek Jeter's most iconic defensive plays.

The first play, commonly called the "jump-throw" is known across the world by almost any baseball player or fan.  It starts with a sharply hit ground ball towards the hole between Jeter and third base.  Looking at simple kinematics- based relationships, it is a large feat in itself for Jeter to be able to intercept that ball by moving as far and as fast as he did.  Next, he calculated the exact flight of the ball as it hopped into his glove, and then with the full momentum of his body taking him away from first base, unleashed a powerful, incredibly accurate throw that beat the runner and ended the inning.  Critics say that the only reason that play was made was because Jeter didn't have the speed to get to balls hit away from him, but nobody can deny the fact that the throw, made perfectly, despite the fact he was traveling at a constant speed away from his target and being accelerated back to earth by gravity, is one of the greatest of all time.

Another iconic Jeter play, made in a pivotal playoff game against the Oakland A's shows just how good of a physicist Jeter was.  The play began as a defensive error by the right fielder.  He made an awful throw trying to get the tying run out at the plate.  He missed the 1st baseman who was supposed to relay the throw home, and instead sent it sailing into the grass by the 1st base dugout.  All of the sudden, Derek Jeter came streaking across the field, and on a full sprint fielded and backhand flipped the ball to the cathcer, Jorge Posada, who nailed Giambi with a quick swipe tag to preserve a 1-0 Yankees lead.  The physics come in when Jeter released the ball.  Travelling at over 15 mph, Jeter knew exactly what vertical and horizontal angle  to launch the ball at in order for it to be delivered to Posada to enable a smooth tag.  In the video, one can clearly see how the ball seems to curve as it is being delivered to Posada.  This is because the ball is moving in all 3 directions at once.  It is moving forward with the force of Jeter's "push", sideways with the constant velocity supplied by the sprinting body, and downwards due to gravity.  By correctly judging all three of these factors and many more, Derek Jeter was once again able to make himself into baseball legend with the flash of his glove and the flick of his wrist.

Here is a video of some of Jeter's best defensive plays.  It starts off with The Flip and his Jump-throw is at 2:44.

56 days....

Getting hit by the ball in baseball is just a fact of life.  Many plays in a game consist of players simply knocking the ball down with their bodies in order to better control it or keep it from getting past them.  Usually the ball impacts a part of the body that can take a good amount of force without too much pain (like the torso).  Rarely, and usually by error of the fielder, the ball can find its way to less ideal areas of the body.  In my case, playing the awkward bouncing grounder on old indoor turf the wrong way resulted in the ball settling on a spot right in the lower part of my forehead.  When the batter hit the ball, it took one high hop and I moved backward to catch the ball at the apex of its second hop.  When the ball hit the ground after the second hop, its rotational velocity was very high, and the turf provided the perfect surface for the ball to grip the ground and convert that rotational energy into translational energy, therefore increasing the speed of the ball.  I was not ready for this sudden speed increase and so when the ball got to me the glove was to low, so it bypassed my glove and continued straight into my face.

Currently on my forehead, one can see the stitches imprinted into my skin and also broken skin where the speed at which the stitches were rotating caused them to damage the skin in certain places.

Using physics to think through the situation helps me understand why that second hop on artificial turf is always so annoying.

## The Physics of my Job

62 days until the first Varsity Baseball game of the season (@ Arcadia if anyone's interested)

My job is a pretty simple one: I work behind the snack bar counter at Lakeshore Hockey Arena and cook food for anyone who cares to buy it.  Its not hard and can be fun depending on who you work with but there is one thing that really aggravates me: the french fry bags.  The bags have perforated tops to make opening and pouring the fries out of them easy.  A major drawback is made very clear though when you open a new case of fries you try to pull the first one out.  The boxes they come in should really only hold maybe 5 bags of fries but instead come jammed with 7.  All of these bags scrunched together, paired with the fact that the only way to pull them out of the box was by grabbing the (perforated) tops of the bags, what would frequently happen to me was I would tear the top off of the bag, opening the fries in the process of taking out of the stock freezer.  This made my boss very upset every time he noticed a bag of opened, freezer burnt fries sitting in the snack bar freezer.  To save myself from my boss, I tried to think of how I could possibly grab fries without ruining a whole new bag... Then one day instead of grabbing the first bag in the box, I grabbed the middle one and it came out perfectly.  It had dawned on me that maybe the rough cardboard at the end of the box was causing more of a frictional force on the bag than the perforation could handle.  I tested this theory one day by grabbing a bag from the middle of the box- one that was surrounded on both sides by smooth plastic bags which had a smaller coefficient of friction and therefore less force than the cardboard- and since that day I have been grabbing from the middle and my boss isn't yelling at me anymore.

So use physics- it makes your boss happy.

## Rounding the Bases

A small yet very important technique in baseball is a player approaches, touches and leaves a base during a play.  The idea is, from a physics perspective, to translate as much kinetic energy as possible around a 90 degree angle in order to continue to the next base with a large amount of velocity.  The major part of the technique happens before you even touch the bag.  During the approach, the runner must bend away from the baseline and then come back to the base in a way that makes the turn longer and less of an angle.  (watch the video it this doesn't make sense)  What longer distance the runner must travel is easily made up for by the burst of speed he gets when he pushes off the inside part of the base with his right foot.  Contacting the inside of the base with his right foot allows the runner to line his body up perpendicular to the face of the base and really push off of the raised base to use Newton's 3rd law to his advantage.  Looking at this from a kinematics perspective, one can see that the increased velocity, coupled with a more direct route to the next base greatly increases the likelihood of reaching that base safely.

In the video below, go to 1:00 and look at #47, Howie Kendrick.  Although this is an amazing throw by Cespedes, it is one Kendrick could have easily score on if he had rounded third correctly.  You can see that he is many feet away from the 3rd base line which means he rounded 3 at a speed that was too great at too sharp of an angle. This curved route meant he probably had to run 5 or 6 feet more than the actual 90 feet that separates 3rd and home.  A better turn means he is safe without a doubt.

## Fastball Physics

I have been wanting to do a post on the physics behind a fastball for a while... and because of the events that transpired early today I think this is a fitting time to do it.

Today, Yordano Ventura, 25 had his life taken in a car crash in the Dominican Republic.  He was a pitcher for the Kansas City Royals and was widely regarded as a pitcher that most announcers describe simply as "electric".  Usually I use physics here to bring to light how truly difficult baseball is and the skill of the players who compete for a living.  But as someone who has watched Yordano, I can say even physics have trouble doing his fastball justice.  With fastballs that easily get up to 100 mph, it can be calculated that in just .41 seconds, his pitch goes from in his hand to into the catcher's glove.  As a comparison... an average blink is anywhere from .3-.4 seconds.  W:hen Yordano pitched you could almost literally say: "don't blink, or you'll miss it".  Added to this is the fact that by using the magnus effect to his advantage, Ventura's fastball moves from left to right and even seems to rise, defying gravity.  Any abover- average major league hitter can destroy a straight, 100 mph fastball, but almost nobody can put that same power on a 100 mph fastball that is moving side to side and seemingly against gravity.

Here's a video of Yordano Ventura pitching in the biggest game of his career: Game 6 of the World Series.  He said he was pitching this game for his late countryman Oscar Tavares, another young, promising athlete who himself had died in a car crash.

## Physics in the Body During Combat

This past semester I took "History of Warfare", a half-year elective that took an in-depth look at all major US wars since WWI.  On the last day of the class, we shifted focus to the homefront and talked about mental injuries veterans sustain and how they try and cope after war.  One thing that really shocked me was the existence of a fairly recently discovered injury called Traumatic Brain Injury (TBI).  What surprised me even more was the way in which this injury was sustained.  Essentially, the supersonic winds created by explosions cause the brain to rock inside the skull over a time period of about 3 milliseconds.  What is amazing (and very concerning) is the fact that these winds can impact anyone in the blast radius of 1 foot to up to 1 mile.  The brain even moves so fast that your body doesn't even know its happening... and because of this it is an injury that over 200,000 living veterans suffer through every day.  The symptoms can be compared to CTE in football players and leave veterans feeling "punch drunk" just like the worlds most famous boxers.  The physics come into play when the blast wind hits the body.  First off, the shock of the wind is transmitted to the body as a wave of energy and any surface (like a skull or helmet) can reflect the wave, meaning it can impact the brain 3-5 times per explosion.  In WWI, when the symptoms were first being documented, leading doctors thought the kinetic energy of the blast traveled up the spinal column and into the brain.  Now, there a are theories that go so far as to say shock waves of kinetic energy can reach the brain through the bloodstream.  Although the injury is very serious, it is interesting from a physics perspective to think about the energy transfer happening between those billions of particles through the bloodstream, spinal cord or skull.

P.S.- Anybody with a free period should see if they could get into this class for the new semester.  Its an eye-opening class that was definitely a great choice of an elective.

## Safety Bases

A new development in baseball, especially in Little League, is the implementation of breakaway "safety" bases that rely totally on friction with the ground to stay in place.  The idea behind them was that younger players, who had not yet perfected sliding, were getting hurt when they slid into a immovable base and hurt themselves from the sudden deceleration of their body.  With their leg (mostly the knee and ankle) bearing the brunt of that force, it would make sense to take every precaution to prevent potentially career altering injuries at such a young age.  The key to breakaway bases is the low coefficient of friction that the base has with the anchor it sits on.  This property allows the base to slide off of its platform with the player, decelerating him over a longer time and distance, therefore reducing the chance of injury on a slide.  Simple yet effective innovations like these make the games we love to play a lot more safer and enjoyable for people of all ages and skill.

## The Physics of Tommy John

I thought I would do a quick post about some very interesting information I read about pitching and how it ties in with bio-physics.  As a lot of people know, Tommy John surgery is a dreaded operation that is used on mostly baseball players to correct the mother of all baseball injuries: a UCL tear.  The UCL, or Ulnar Collateral Ligament is a small ligament on the "pinky side" of your elbow.  Its main purpose is mainly to hold back all the torque generated by your arm when it goes into a whipping overhand motion.  Basically, its a convenient little piece of tissue tailor made for all of us throwing sport athletes.  The weird (and kind of scary) part is, for how much throwing revolves around this ligament, us humans punish it all the time.  In fact, multiple studies conducted among college and pro baseball pitchers have repeatedly shown that the UCL sustains anywhere from 65-70 Nm of torque on any given pitch.  And the point of complete failure for a UCL in a lab?  A mere 35 Nm of torque... In other words, every throw, athletes can be putting up to DOUBLE the amount of stress on their UCL than what it takes to completely snap it.

Although this is a scary thought, one may wonder, "this must all not be true because I've never had an UCL injury before".  And although that statement is true, it raises another very valid point: mechanics.  The only reason the MLB does not see an average of 1 UCL failure per pitch is because of attenuation.  Basically the whole reason you twist your core, drive with your legs and tuck your opposite arm when you throw is to attenuate the torque on your elbow.  To put it simply, all of your body parts "help out" your elbow and contribute in their own way to driving the ball forward, meaning the velocity of the ball does not depend solely on your elbow and therefore all that 70 Nm of torque will not be put directly on your UCL.

So remember kids: attenuation is what is saving you from a career ending injury... so practice those mechanics!!

## The Physics of Deshaun Watson

Thank God I'm a Clemson fan...

Saturday was an awful day for me watching the Raiders fall to the Texans; but Monday was a different story.  My Clemson Tigers won the College Football Playoff Championship with a thrilling victory over Alabama.  It was one of the most exciting games I have ever watched and was definitely well worth staying up till almost 1 on a Monday night.  Although I could talk about the physics of Deshaun Watson holding up the National Championship Trophy, that would be a little too similar to my last embarrassment of a blog post.  Instead I want to talk about the rotational velocity of Deshaun Watson during one especially big hit put on him during the game Monday.  As I was watching the game and I saw Watson helicopter through the air, my first thought wasn't: "Is he ok???" It was more: "Hey! what a great idea for a blog post!"  So here I am, about to calculate the rotational velocity of Deshaun Watson.

As you can see by watching the video of the hit below, Deshaun was sent into the air and from hit to re-contact with the turf, his flight took approximately one second.  He rotated almost exactly 1.5 times and therefore, using rotational kinematics, we can find that he was rotating at over 9 radians per second.  Converted to rpms and that would equal 90 almost exactly.  Now most people cant put 90 rpms into context, so here's another way to look at it: Deshaun Watson is 6'3", which means layed straight out, he forms the diameter of a circle that is 75" long.  When calculated, the circumference of that circle is 235.7 inches, and knowing that his head and feet traveled 1.5 circumferences, we can calculate that his body parts on the outer edge of the circle whipped around at 19.9 feet per second.  Converted to mph, thats 13.4 miles per hour! That may not seem like alot but just imagine sprinting at someone and colliding helmet to helmet  at over 13 mph.  That wouldn't feel too good!

This is exactly what could have happened to Deshaun's head but with the additional force of that other person- running at speeds of up to 20 mph- exerted on his head.  Although I know the math is far from perfect, thinking about football through physics like this makes one appreciate how these athletes put themselves on the line for the games they love.

## The Super Bowl

Today at 4:30 Eastern Time something magical will happen.  THE Oakland Raiders will take the field in a NFL Playoff game for the first time in 12 years.  There are a lot of questions surrounding the Raiders and their chances of even making out of the wildcard round.  Their chances are pretty good as long as they can overcome the Texan's defense, who is 1st in the league in the overall category.  Being the overconfident Raiders fan I am, I predict the Raiders are going to play not one, but two games in Houston before the end of February.  (Houston is hosting the Super Bowl this year).  The only question I have is a big one about rookie Connor Cook.  Obviously to be in the NFL you must be strong, but as a rookie, it is common that players haven't yet developed into their full physical potential.  This being said, the Vince Lombardi Trophy is 7 pounds in weight (3.2kg).  This means after playing the game(s) of his life, Cook will have to hold 32 Newtons of force at bay while hoisting the Lombardi Trophy victoriously into the air.  Depending on conditions, he may also have to deal with a slight torque force if the wind is significant.  As we know, the farther away a torque is from its axis, the harder it is to control if that axis is your shoulders.  Based on these numbers, I believe Cook will have no problem lifting the trophy and winning the Super Bowl for the Silver and Black.

I apologize for my- what some may call- overconfidence and I ask that in the likely case the Raiders lose today you don't make fun of me too much for this.  Thanks!

## Wood Bats

This Christmas I was lucky enough to get my 4th wood bat from my parents. (Sorry dad for breaking the last 3)  As I was holding it in my hand I noticed it felt lighter than my previous bat, but what confused me was the fact that both had the same length and weight.  Using my ever-expanding knowledge of physics, I got to thinking about it and a few minutes later it dawned on me that its really not that confusing at all.  Despite how un-exact of a science you may expect making wooden bats may be, (after all they are still made by using a lathe and cutting tools) there are exact model types of wood bats that tailor to different types of hitters.  For example, the 271, the most popular model in the MLB features a medium barrel, handle and tapered knob to balance out the weight along the whole length of the bat.  This gives the batter a more balanced feel and is ideal for guys looking for a good balance between contact and power, push and pull hits, etc.  This was the model of my new bat, and to compare, my old wood bat was a 243.  This model is less popular because it appeals to only one kind of hitter.  Anybody looking to drive the ball out of the park, and who doesn't mind a few bad misses, would love the 243.  When held compared to the 271, it feels a good amount heavier because it features a large, long barrel and a skinny handle.  Using the equation for torque, one can easily see how with more of the weight located farther away from the point of rotation (in this case, my hands), the bat barrel will exert more force towards the ground and therefore feel heavier.

This same idea translates into hitting the baseball.  With the 271, considerable power is lost because the handle, which has very low energy during the swing due to where it is positioned in relation to the point of rotation.  There is alot of mass in that part of the bat, mass that is not allowed to contribute to the kinetic energy of the end of the bat, which is the part that collides with the ball and sends it flying.  With the 243, although the added torque makes it harder to control, the mass added to the barrel of the bat pay the hitter back in dividends when the ball is propelled with an energy far greater than the 271 just due to the added mass in the barrel.

It seems like a no- brainer to use the 243, but hitting a 95 mph fastball with something that, when compared to the more balanced 271, feels like a sledgehammer is something that only the strongest and most coordinated hitters- and most of those players sacrifice dearly in the average department for a few extra home runs.  Knowing this about wood bats, I will definitely be more picky about what I swing in the future- all thanks to physics.

## The Physics of Khalil Mack

I know this blog is all about baseball but sometimes special moments must be capitalized upon... and this is one of those moments.  In light of the great ball game my Raiders had today (hey Justin ) I thought I would do a blog post on the best defensive end in the league: Khalil Mack.  His tipped pass in the 4th quarter and strip sack later on pretty much sealed the game for Oakland and in particular I want to focus on the tipped pass.  Believe it or not, the physics behind this play are pretty interesting and I had a lot of fun thinking about this play.  It all starts when Mack used speed to his advantage to run around the outside of the offensive lineman.  By doing this, he was able to keep most of the force from the 300+ pound lineman from impeding his velocity and momentum.  Because of his speed built from accelerating into the pocket, he could then take a looping path to Tyrod Taylor and still have time to have an effect on the pass.  Using his incredible strength coupled with speed he fought off both the lineman and the centrifugal force resulting from the circular path and got a had on the ball and Taylor's arm.  At the point of release, other than gravity, the ball had 2 fources acting on it.  It was being propelled forward by Taylor's hand and then the frictional force from Mack's hand was both restricting forward movement and causing end-over-end rotational movement.  This combination in forces put unwanted torque and other outside forces on the ball that resulted in a week, wobbling pass that was picked off by safety Nate Allen inside the Red Zone.

Basically all of this physics talk is just a long way of saying one thing: Khalil Mack is a beast.  Good game Buffalo.

Here's a link to the video of the play.

And for your additional viewing pleasure, here's a video of my favorite player right now, Marquette King and yet another stupid way to get a penalty in the NFL...

## The Physics of Bow Hunting

This long weekend, my family took a vacation up at my cottage near Watertown NY.  My father, brother and I all hunt and have been doing so since a young age and every fall we take time to spend some time in the woods with each other hunting for big game.  This time of year, bow hunting is the open season, and sitting in my tree-stand this past weekend, I thought back to a time when my brother and I were first learning about hunting and archery.  My brother, who was 11 at the time was enjoying his fancy brand new bow with sights and everything.  He had sighted the bow in so he could aim directly at the target from 10 yards out and the bow would be oriented at just the right angle so the arrow would arc and hit the target right in the middle.  Now, thinking he was Robinhood, Chad took it upon himself to get into the treestand we had set up to practice with and declare to the world his amazing archery skills.  The next 5 minutes were easily the most frustrating of his life as he proceeded to miss the target on every shot he took, getting closer to tears every time he had to get off the stand and retrieve his arrows after a full round of misses.  Obviously, 11 year old Chad did not understand simple trig and physics because when one looks at the situation closely, it is easy to see why he missed.  The treestand was 15 feet off the ground and against a tree, which formed a right angle with the ground. This right angle meant that the direct path from bow to target was a hypotenuse of a right triangle, therefore meaning the path was farther than 10 yards.  With his bow sighted in at exactly 10 yards, it is obvious that without compensating, the arrow would miss low.  In addition, with Chad being young and not very strong, the bow had to be reduced in power for him to be able to pull back and shoot accurately.  This lack in power meant a lower velocity of the arrow and therefore more time in the air.  Through kinematics, this means there is more time for gravity to accelerate the arrow downward, increasing the amount of error in his shot.

And because you are probably so surprised I havent talked about baseball at all, here's a picture of one of the game's best pitchers Madison Bumgarner who is an avid hunter.

## The Crowhop

Keeping with my outfield theme, Crowhops are critical to the outfield position.  A crowhop is a shuffle-step like movement that allows a fielder to throw the ball with greater initial velocity and therefore more distance.  Although I've been around the game for over a decade, the physics behind the crowhop never really seemed interesting until you take a deeper look.  Standing still, a player can still throw a ball with tremendous speed.  All of this velocity is coming from the muscles in the arm and torso as the body is whipped through the throwing motion.  When a player crowhops, they are simply adding initial velocity by moving their body towards their target and now, with the same force as before throw the ball substantially harder.  One thing you may see players do is fall down or somersault after a crowhop throw in an effort to achieve as much follow through as possible.  The follow through is critical because the longer you keep your hands on the baseball, the longer your force will be imparted on it and therefor the larger the velocity the throw will have.

Enjoy these impressive outfield throws made possible by using a crowhop!

## The Physics of a Gold Glover

Tonight, the 2016 Gold Glove Awards were presented.  For those of you who dont know, the Gold Glove Award is given to two MLB players for each defensive position that had exceptional seasons playing defense (making athletic plays, committing few errors and so on).  The award is given to two players per position because a winner is chosen from the two main leagues under the MLB: the National and American Leagues.  One particularly fascinating position from a physics standpoint is the position of outfield.  To the innocent bystander, a strong defensive outfielder looks to have the easiest job on the field.  They have the longest time to field the ball and almost never have to quickly throw it to beat a fast runner.  They just jog around catching balls that the batters lob up in the air.  What most people dont realize, is that outfield is really HUGE, and the longer time it takes for the ball to get to the fielders means just more time for physics to play with the ball in extreme ways.   Lets take the outfield of the World Champion Chicago Cubs for example... the total area of grass in the outfield is roughly 90000 square feet.  This means on any given play, a major league outfielder can be expected to be in charge of give or take 30000 square feet of turf!  To cover this insane amount of ground, elite outfielders can get up to over 20mph while hustling for the ball, and all the while they are tracking data such as launch angle, apex height, projected landing and initial exit velocity.  All of this is estimated mentally and happens within a few seconds of the contact of the bat.  Another huge factor in tracking a fly ball is the spin, which leads to the Magnus Effect.  With balls leaving MLB bats at anywhere from 90-105 mph, the rpms on the ball can be even greater than what was put on it by the pitcher.  This Effect can move a ball several inches from the mound to home (which is 60.5 feet away) so just picture how many tens of feet the ball can move because of the Magnus Effect when it is driven distances exceeding 300 feet.  Using all of this, outfielders need to calculate one thing before they even move: projected landing spot.  In the video below, Reds outfielders Tyler Holt and Billy Hamilton both make amazing plays in the ninth inning to help keep a four run lead over the Phillies.  Notice, when the STATCAST metrics come up, how fast their first step was and how efficiently they ran their route.  These stats are amazing because in less than half a second, both fielders knew exactly where to run to get to their projected landing spot.... and they ran to that spot with over 93% accuracy.  Nobody but a baseball player could project the landing spot of a ball spinning over 1000 rpm and travelling at over 85 mph within a 93% accuracy in under .5 seconds.  When you think about outfielders like this, you gain a whole new appreciation for the players and the true brainpower and athleticism that goes into a seemingly easy position.

So that leads me to believe: maybe people dont play right field when they are young because they are seen as bad, its just because they have a very promising future as a physicist...

## Physics in Cleveland

Last night, in Cleveland, two landmark events happened in a city mostly considered the laughingstock of sports.  In one night, the Indians won game one of the World Series against the Cubs and the Cleveland Cavaliers hoisted their Championship banner on opening night of the NBA regular season.  With these stadiums right across the street from each other, it got me to think: with Cleveland fans so starved of sports success, they took full advantage of this opportunity to be loud and support their beloved Cavs and Indians.  With the sheer volume coming from each stadium last night, I also wondered what kind of noise would disperse into the surrounding city.  With these thoughts, I went ahead and made a visual representation of the sound waves coming out of each stadium and the possible sites of constructive and destructive interference.  Although the possibility of me going back in time and going to Cleveland and actually seeing if there is detectable interference is slim to none (most likely none) its still cool to wonder what a passerby in Cleveland would hear if they are going in-between the two stadiums who were louder than they had been in years last night.

The feat of checking a baseball swing is truly one that requires much physical power.  The majority of people compliment the batter's keen eyesight when he stops his bat mid swing, when in reality they should be complimenting his strength.  Thinking about it from a physics perspective, it is simple to see how much strength is required to stop a swing.  250 milliseconds after the ball is released, the batter starts his swing, generating all the force he can out of muscles in his arms, legs, hips, shoulders and abdomen.  If he were to commit to it, the next 150 milliseconds would be spent taking a complete swing at the ball.  If he changes his mind, he must do so within 50 milliseconds of the start of his swing for a very important reason: he must slow the bat back down to rest using the muscles in only his upper body, taking his hips and legs out of the equation.  Compared to the arms and shoulders, the lower body generates a force considerably larger.  This means, if applied to kinematics, the roughly 50 milliseconds of full force, full body swing, could only be stopped with roughly 100 milliseconds of full force from the batters upper body in the exact opposite direction.  With MLB swings clocking in at over 80 mph, it is a true physical marvel that these players can stop their swing in such a short period of time.

To take this a step further, we can even estimate the force a batter needs to apply to the bat to get it to stop within that 100 ms time frame.  Given that the swing is 80 mph and the batter has exactly 100 ms to stop his bat, we can use  $a=\frac{v_{i}-v_{f}}{t}$    to determine the the acceleration of the bat when the opposing force from the arms is applied.  By plugging in the values converted to m/s and s, we can find that:  $a=\frac{-35.7 \frac{m}{s}}{.1s}=-357\frac{m}{s^{2}}$ . This means that using his upper body, the batter is decelerating his bat at -357 meters per second squared.  Plug this into the force equation  $F=ma$ and assume the league- standard 32 oz (.91kg) bat is being used and you get:  $F=ma= (.91kg)(-357\frac{m}{s^{2}})=-324.87N$ .  Here we can roughly estimate that an average MLB player applies a 325 Newton force to his bat when he checks his swing.  This is just as impressing as it is eye opening... just because they only run 90 ft at a time doesn't mean pro ball players aren't very powerful athletes!

Also, enjoy this video of Yasiel Puig, one of the strongest guys in the league actually break his bat because of how fast he decelerated his hands.  Enjoy!

## Playoff Physics

In the short period of time I got to watch the Dodgers/ Cubs game before I started working on my physics, I noticed a strange game plan that the Dodger base runners were employing against Cubs lefty pitcher Jon Lester.  After a four pitch walk to lead off the bottom of the first, Dodgers player Enrique Hernandez started to bounce back and forth and side to side as he was taking his lead from first, trying to distract Jon Lester from his task of pitching.  To people who aren't familiar with the game, a left handed pitcher is oriented on the mound so his body faces first base.  This means whenever he is looking forward, he always will see the base runner.  Usually, a base runner keeps a low, explosive stance to aid him in reacting in a moments notice to anything that my happen on the field.  In Lester's case, the runners tonight moved in every direction possible to distract Lester.  The runners knew that he is a pitcher who doesn't like to try and pick people off so they took advantage of that by getting huge leads and trying to get into his head.  Personally, I do not think this strategy is beneficial for one main reason.  If Lester decides to pick off at the right moment, he can catch the base runner with all of his momentum heading away from the base, the runner will have to apply a huge force to totally reverse his motion and dive back to the bag.  This split second of decelerating, stopping, accelerating and then even decelerating again due to the friction of the dirt as he slides into the bag, gives Lester ample time to deliver even a mediocre throw that will nail the runner.  This chance is a huge one to take, especially for a team up against one of the best pitchers on the best team in baseball.  If LA wants to win tonight and take a 3-2 lead in the series, they will have to be smarter on the bases.

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