By:

 Hiep and Long

Table of Content

*Newton's Laws of Motion  *Center of Gravity *Projectile Motion  

*Friction *Aerodynamics *Momentum  

Law of Inertia

*When a soccer ball is in motion, it will stay in motionWhen a soccer is at rest, it will stay at rest why? Newton's first law says that it's just the natural tendency of objects to do what they are doing. The reason a soccer ball move is because of unbalance forces like a soccer players kick.

Newton's 2nd law

 F=ma  

Force = mass X acceleration  The acceleration of the ball dependson how hard the kick was dividedby the mass of the ball

    

Newton's 3rd law

For every action, there is an equal andopposite reaction    When soccer ball is kicked, the kicker experience the same amountof force the ball experiences  *If you kick a ball once really hard and oncereally soft, you can actually experience the differences of how hard the ball kicks back atyou

    Center of Gravity

Because the soccer ball is a sphere,its center of gravity is in the center. This means its trajectory is more easily predictable, unlike a football where its shaped like a cone.

            The human body is oddly shape and our center of gravity usually     is near the pelvis. However, our center of gravity can change,     especially during sports. This       goalie swiftly changes his center of gravity to try and block the ball 

Projectile Motion

When a soccer ball is kick in the air, it becomes a projectile.

Its predetermined path is a perfect parabola, but in soccer, wind factors comes in to play thus making the game more difficult

           Friction

 

*Friction is what causes the ball to stop moving when it is kicked on the

grass. 

*Friction occurs because of the electromagnetic forces between charged particles of the grass and the skin of the soccer ball rubbing against each other which constitute the surfaces in contact. 

*Friction turns kenetic energy into heat.  -Yes! That means if you kick a ball hard enough, the ball can actually catch on fire.-

    

Drag

 *Drag occurs when a ball kick moving through the air *As the ball is pushing through the air, the air pushes back thus slowing it down *Drag is the reason the ball doesn't travel in a perfect parabola. *A sphere experiences 90% of Form Drag. *A way to decrease drag is by kicking the ball with a spin. Once the ball spins, the magnus affect takes place. The magnus affect decreases air resistance drastically.

MAGNUS AFFECT

            How it works

*If the ball is moving through the air with a velocity X, the velocity of the thin layer of air close to the body is actually a little greater than X on the forward-moving side and a little less than X on the backward-moving side *The Forward moving side of the ball usually determines the direction of the ball.

*When a projectile flies through the air with a rotation, its path will be curved.*As the ball is traveling through the air, it creates a whirlpool of fluid around itself and will experience a force perpendicular to the line of motion

      S    is for the air resistance  

coefficienct  across the surface of the ball                     is for angular velocity vector                     is for resulting force          V    is for velocity of object

Funny soccer joke ~Reporter: How does understanding the laws of motion help with your game?Roberto: There are laws?

 

The harder you kick a ball the more curve it will experience.  Curving ball is use to be trick goalies and to score amazing goals like this one from 35m out

 

Momentum 

p=mv Ever tried stopping a moving ball? Hard huh. Ever wonder how soccer player stop the ball so effortlessly? Easy, its all about timing. Instead of just stopping the ball by putting their foot out, they go with the ball and slows the momentum down with time. They stop the ball by slowing resisting it, instead of quickly blocking it. 

 

 With these knowledge of soccer, you can now understand how soccer works and why it works that way. Now you can start using this knowledge to improve your game. Its simple! So go out there and start scoring goals!