What You'll Get
Choose Between Two Options
- $150 for seven-week developmental soccer training program for one child aged 5–13 ($250 value)
- $300 for seven-week developmental soccer training program for two children aged 5–13 ($500 value)
Bending the Ball: A New Spin on Soccer Shots
Whenever a soccer ball curves, seemingly changing its orbit in midair, NASA scientists may rush to classify it as a planet. But in fact, the movement is due to yet another physics concept pioneered by Isaac Newton: the Magnus effect, a phenomenon first described in regard to tennis. Newton noted that topspin made the ball dip, whereas backspin made for a straighter trajectory. In other words, the way a ball spins affects its path in the air.
Usually, a ball curves in the same direction in which it’s spinning; air moves with the ball on the side that spins forward, pushing it in the other direction. A ball spinning counter-clockwise, for example, tends to bend to the left. But a ball’s movement may not always be so easy to predict. Its trajectory is also affected by the smoothness of the ball’s surface. In fact, a perfectly smooth (or laminar) ball would likely curve in the opposite direction of a rough-surfaced (or turbulent) ball when kicked in exactly the same manner.
Of course, nobody plays soccer with a perfectly smooth ball, despite the substantial benefit it would have on blooper-reel ratings. Even so, different stitching patterns do alter the roughness of a ball’s surface. This is why there seems to be a controversy every four years over a new ball design—even the coolest new look can have a drastic effect on a ball’s in-flight physics.
The Fine Print
Promotional value expires Sep 3, 2016. Amount paid never expires. Must sign waiver. Registration required. Subject to availability. Merchant's standard cancellation policy applies (any fees not to exceed Groupon price). Limit 1 per person, may buy 1 additional as gift. Valid only for option purchased. Valid only for children ages 5–13. Merchant is solely responsible to purchasers for the care and quality of the advertised goods and services.