Celebrating is contagious. Studies in recent years have shown that players who score a goal and then celebrate by raising their arms actually pass on their enthusiasm to the next guy to take a shot. Same thing when a player misses and slumps back over to the sideline.
Take your time. Players who kick the ball within a second of placing it usually miss. Those who take longer to set and aim do better.
Physics also plays a role in both penalty kicks, and free kicks from the corners or other parts of the field. This year at the World Cup in Brazil, a newly-designed soccer ball may even the playing field for bigger, stronger players and those who are smaller.
John Eric Goff, professor of physics at Lynchburg College and author of "Gold Medal Physics: The Science of Sports," teamed up with two Japanese scientists to study the motion of Adidas’ new soccer ball, known as the Brazuca (Brazilian for national pride, or a native of Brazil).
Wind tunnel tests were used to study the new ball and the one Adidas used in South Africa in 2010 known as the Jabalani. It turns out that the new ball is likely to be more predictable, and flies through the air with less drag at lower speeds. That could help some of the underdog teams who kick the ball at 40 to 45 miles per hour, compared to the 60 to 70 mile per hour shots by the top players, Goff explained.
This year’s ball is also less erratic. That’s because the ball has more roughness on the surface, which causes a slight amount of turbulence on the surface and reduces drag. A similar principal is at work in a dimpled golf ball, Goff said.
Good penalty kickers, in addition to getting their heads straight, also have mastered the art of spinning a soccer ball while kicking it forward. This counter-clockwise spin (for right footed players) gives the ball a slight arc on its way to the goal -- often confusing the goalkeeper.
“It requires skill,” Goff said. “You have to spin the ball just right.”
Using spin, the best players can curve the ball right around a wall of players and into the goal. That’s because they’ve harnessed the Magnus force, a principal of physics initially discovered by a 19th century scientist who noticed it while studying the trajectory of Civil War bullets.
When the World Cup opens Thursday afternoon with Brazil taking on Croatia, Goff said he’ll be watching.
“These are golden opportunities for scorers,” he said about the combination of physical forces in play on the field. “I’m going to be looking at these trajectories quite closely to see what kind of spin and speed they can develop.”