What causes a thrown baseball to curve?

[nst.john]

I'm an avid baseball fan and since I've gotten interested in physics, it's pretty cool to try to combine the two.

I was wondering what forces act on a thrown baseball and how the spin and the seams of the ball cause it to curve.

 

[dauto]

As the spinning ball moves through the air, the surface of the ball drags air molecules along with it causing the air pressure to be slightly larger on one side of the ball (and smaller on the opposite side) This pressure differential creates a sideways force on the ball curving its path. This is called Magnus effect.

 

[rcgldr]

The airflow near the surface of the ball remains "attached" longer on the side that is spinning backwards from the direction of travel, causing the air in the "wake" left behind the ball to get diverted a bit towards the side that is spinning forwards from the direction of travel. Wiki article:

http://en.wikipedia.org/wiki/Magnus_effect

 

[Chestermiller]

I'm an avid baseball fan and since I've gotten interested in physics, it's pretty cool to try to combine the two.

I was wondering what forces act on a thrown baseball and how the spin and the seams of the ball cause it to curve.

If you are interested in the physics of baseball, look up on Amazon the book entitled "The Physics of Baseball" that came out a few decades ago. It is still very popular, and gives good explanations.

Chet

 

[PJC01]

I can explain the phenomenon of a curveball using principles of physics. When a pitcher throws a curveball, the ball is initially moving in a straight line towards the batter. However, the spin of the ball creates a force known as the Magnus effect. This force is caused by the difference in air pressure on either side of the ball due to its spinning motion.

As the ball spins, the air on one side of the ball moves faster than the air on the other side, creating a difference in pressure. This pressure difference causes the ball to curve in the direction of the lower pressure. In the case of a curveball, the spin is typically in a downward direction, causing the ball to curve downward towards the ground.

In addition to the spin, the seams on a baseball also play a role in its movement. The seams create turbulence in the air around the ball, which can affect its trajectory. Depending on the type of pitch and the angle of the seams, this turbulence can either enhance or disrupt the Magnus effect, resulting in different types of movement such as a curve, a slider, or a knuckleball.

It is also worth noting that the speed and direction of the pitch, as well as the air density and temperature, can also impact the movement of a curveball. These factors all interact to create the complex and unpredictable movement of a curveball, making it a challenging pitch for batters to hit.

In conclusion, a curveball curves due to the combination of the Magnus effect and the interaction of the seams with the surrounding air. It is a fascinating example of how the laws of physics can be applied to explain real-world phenomena, and its mastery requires both skill and understanding of the principles at play.