Physics and science behind the baseball

 
1. A curve ball is created when a ball is spinning.
2. Pitchers as they throw the ball, snap their wrist in a turning motion, to make the ball spin.
3. There occur three forces: weight, drag and Magnus force.
4. Weight depends of ball mass making the ball falling to the ground.
5. Drag depends of velocity and the density of air slowing the ball.
6. The Magnus force affects the motion of a ball in the air. The amount of this force depends on amount of spin, speed of pitch, and density of the air.
7. The air flows around the spinning ball faster on one side and slower in the opposite side.
8. The faster flowing air creates less pressure in one side of the ball, which forces the ball to change its trajectory in that side.
9. To find the spin direction there is a rule called screw rule. When turned clockwise the screw moves in (toward the screen, the paper, etc.), and when the motion is counterclockwise the screw turns in the opposite direction. If the rotation is made conforming to the spin the screw movement indicates the spin direction.
10. To find the direction of Magnus force there is a rule called the right hand rule. The spin direction is forwarded toward your palm, the right index finger points in the direction of the velocity vector, and the thumb points in the direction of the Magnus force.
11. As the force acts on the ball, it is deflected along the flight path giving the ball's trajectory.

Conclusions

1. As the force depends on density of air the same ball pitched on a stadium on a sea level is different than one pitched on a stadium at high altitude (the air density is lower on high altitudes).
2. If the force is oriented upwards the ball trajectory is longer and lifted.
3. If the force is oriented downwards the ball trajectory will end with a dramatic drop on the plate.
4. If the ball is thrown with a sidespin, the force always is acting perpendicular (at a right angle) to the flow direction, resulting a circular arc flight path.
5. Pitchers use combinations of spinning to create a particular ball flight path.