Surprisingly an outfielder needs to know physics to play good baseball in his position. Most people might think that catching a fly ball or a line drive is easy, but in reality it is not. Outfielders have a half of a second to pick up exactly where the ball is going to end up. The first initial reaction to a hit to an outfielder is, is it going to the left or right. The next fraction of the second must be used to see the exact velocity and angle the ball travels off of the baseball bat.
Baseball players, especially in the outfield, are physicists. They need to be smart enough to see the immediate velocity and angle of the ball off the bat from three-hundred feet away, incredible. Now realistically, outfielders have been practicing for years to track the flight of a baseball right after it hits the bat. Maybe it is a small exaggeration that they are able to read the velocity and angle off the bat. This video link is someone showing the physics behind tracking a ball in the outfield.
Not only is there physics involved in tracking a baseball, but also in the energy and momentum transfer. The batter builds up a lot of potential energy to then be transferred into kinetic energy when the ball hits the bat. When the ball is flying through the air and is accelerating towards the outfielder, it builds up speed and momentum. When an outfielder catches the ball, momentum creates an impulse of the glove moving backwards at a speed because of the mass of the ball and the amount of momentum.
Finally, the outfielder must throw the ball into the infield with the most accuracy and efficiency. For the best distance, the outfielder must launch the ball at 45 degrees. But for us outfielders we try to throw the ball on a straight line. This requires more speed and momentum to get the ball into the outfield as quick as possible. When an outfielder has already gone through equations in his head and serious calculations, when the ball is hurling through the air toward him it is extremely important to gain as much momentum as possible. This is only achievable if the outfielder takes three or four steps back and approaches the ball with extra speed to anticipate a crow-hop. A crow-hop is a skip like motion to obtain momentum to use all of your body mass to have a large effect on the baseball.
Once all of the above is achieved by the outfielder, they can then hurl a bullet of a throw into home plate for an amazing play from 350 feet away. Thanks for reading!!