Name: How the Magnus Force Curves Soccer and Baseballs
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When a ball traveling through the air is spinning, some physics known as the magnus force kicks in to make it bend or curve. The magnitude of the magnus force depends on the ball’s rate of spin as well as its mass, velocity, radius, and the density of the air around it.

Baseball vs. Soccer: Which sport has the best curves?

When a ball traveling through the air is spinning, some physics known as the magnus force kicks in to make it bend or curve. The magnitude of the magnus force depends on the ball’s rate of spin as well as its mass, velocity, radius, and the density of the air around it.

How the Magnus Force Curves Soccer and Baseballs

Baseball vs. Soccer: Which sport has the best curves?

Physics & Math

How the Magnus Force Curves Soccer and BaseballsPublished: April 5, 2019Onscreen: Baseball vs. Soccer. Which sport has the best curves? Baseball with its curveballs?David Bush: I try to make it move as much as I can within the strike zone.Onscreen: Or soccer? With kicks like this one?André Akpan: When you hit it right it’s just such a perfect feeling. There’s no specific term. Curve it, bend it. If you want to get funny, some people say they put a little sauce on it.Onscreen: Science may have the answer.Dr. Idaykis Rodriguez: When the ball is in the air spinning, there’s this force which makes it bend or curve.Onscreen: It’s called the magnus force. Imagine a ball flying through the air. As it moves, it pushes the air to each side. Now, imagine the ball is spinning counter-clockwise.Dr. Rodriguez: The air that’s going with the spin is moving faster than the air that’s going against the spin.Onscreen: Friction on one side pushes against the air but pulls air along the other making it speed up and curve around the back of the ball. The action of pulling the airflow around the back of the ball is key because every action has an equal and opposite reaction.Dr. Rodriguez: That’s Newton’s third law.Onscreen: A swimmer propels herself forward by pushing the water backwards. A rocket blasts off by shooting gases out beneath it. The airstream flies off the back of the spinning ball forcing it in the opposite direction.Dr. Rodriguez: This makes the ball go to the left.Onscreen: The magnus force works on more than soccer balls and baseballs. It can make cylinders like this do crazy things. Back to the question: Who curves it better?Dr. Rodriguez: The magnitude of the magnus force depends on the spin of the ball, the velocity of the ball, the radius of the ball.Onscreen: It also depends on air density.Dr. Rodriguez: If there were no air it would just go as straight as possible into its target. The ball carries better in thinner air. If there’s a payer in Denver vs. a player in Florida, the curveball that the Denver player experiences is probably going to curve less than the player in Florida.Onscreen: The ball’s shape matters too.Dr. Rodriguez: If it’s a ball that’s kind of smooth, it doesn’t bend as much.Unknown male: The major league baseball standards are pretty tight. So, generally most balls are almost exactly the same.Akpan: Traditionally most soccer balls have had a pretty standard pattern. But in the last 10-15 years you’ve seen different patterns and styles.Onscreen: The result is that the average soccer ball has gotten smoother. Baseballs still have the same raised stitching. These factors help give you the strength of the magnus force. But calculating the ball’s curvature requires something else.Dr. Rodriguez: To directly calculate the magnitude of the force, you will need the mass of the ball.Onscreen: Here’s the final tally. Baseball is looking strong but the strength of the magnus force also depends on the radius cubed. Soccer wins the curved test.

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How the Magnus Force Curves Soccer and Baseballs

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