Transcript ThePhysic_of_Soccer

By:
Hiep and Long
Table of Content
*Newton's Laws of Motion
*Friction
*Center of Gravity
*Aerodynamics
*Projectile Motion
*Momentum
Law of Inertia
*When a soccer ball is in motion, it will stay in motion
When 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 depends
on how hard the kick was divided
by the mass of the ball
Newton's 3rd law
For every action, there is an equal and
opposite reaction
When soccer ball is kicked, the
kicker experience the same amount
of force the ball experiences
*If you kick a ball once really hard and once
really soft, you can actually experience the
differences of how hard the ball kicks back at
you
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
*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
*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.
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!