Goal Kicks in Soccer

By: Elora Larson and Sara Balcer

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Question:

When it comes to soccer, does physics really have anything to do with the sport?

  • You may not think it's that important, but it really is. Things like knowing which way to kick the ball, and with how much force, along with wind direction and speed are extremely important things to know when kicking the ball from the goal as a goalie

Research


Putting force into your kick is the only way to get the ball to move, and kicking a soccer ball halfway down a soccer field takes a whole lot of force. After the ball is kicked, projectile motion causes the ball to slowly curve toward the ground because of the gravity pulling on the ball. Kicking the ball harder and with more force will cause the ball to travel not only farther, but faster as well. Newton's second law of motion which states F=mass x acceleration will tell you exactly how much force is actually being put into the ball when you kick it down the field. Since the soccer ball is light, it's going to fly through the air faster when you put more force into the kick. If the ball has more air pressure in it, it will also cause the ball to rebound better off a player's foot when being kicked. Being in a place with less air pressure also effects how far and how well the ball will travel when kicked. Less friction is between the ball and the air when there is a lower air pressure, and more friction when there's more air pressure.

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Links To Online Resources:


http://www.life.com/image/80442080


Kicking A Goal Kick


















When you're first going to kick a soccer ball in a goal kick, you have to line it up in the direction you want it to go. You move back so you can get enough momentum and force to kick the ball. Right when you get to the ball, you bring your foot back, point your toe to the ground and kick it with your laces. The ball should go straight if you kick it with your laces. If you kick the ball with the inside of your foot, it will curve. The direction the ball travels through the air, how high the falls goes and also how far it travels are all dependent on the way you kick the ball.

Kicking the ball with a lot of force is important for the ball to go farther and pick up more momentum as it travels through the air. Following through with your kick will help building up force and send the ball flying farther, which will reduce the friction acting upon the ball as it's in the air.

Also, if you want to defy the laws of gravity, it's best if the ball is kicked up into the air, but at the same time kicked far as well so that the ball doesn't drop to the ground as fast due to projectile motion. When the soccer ball is first kicked, it has more momentum put into it so the ball travels farther and faster through the first half of the time the ball is in the air. After a while though, the ball loses momentum and is pulled towards the ground by gravity.

According to Newton's First Law of Motion, the soccer ball will keep moving unless something stops the ball from moving. So as soon as the ball hits the ground, the ball will slow down. But if a player kicks the ball to another player just as the ball is about to hit the ground, the ball will keep moving in whichever direction the person kicked the ball in.

Putting your body into the kick as well will give the ball more momentum when it flies through the air because not only is your foot putting force into the ball, but the rest of your body is too.

Sources Cited:


http://www.soccerballworld.com/Physics.htm
http://www.soccerballworld.com/Physics-FAQ.htm
http://clackhi.nclack.k12.or.us/physics/projects/Final%20Project-2005/3-FinalProject/soccerBall/Forces.html