Transcript powerpoint

How to Bend It Like
Beckham!
A Small Physics Lesson
Who is David Beckham?
English soccer star
Famous for his
“bending” shots
Married to one of the
Spice Girls :(~
What do you mean, bend it?
Click the button below
to see one of his famous
“bending” shots.
So why does it bend?
Three Reasons:
Ball Speed!
Air Movement!
Foot skill!
It’s Physics!
How does speed affect the shot?
Beckham’s shots travel
at high speed: an
2
acceleration of 8m/sec.
The ball is spinning 8 to
10 revolutions /sec.
With this motion, the
airflow around the ball
is turbulent, resulting in
little drag.
Speed….continued!
At some point in its one
second journey toward
the goal, the ball slows
enough for the air
around it to revert to
laminar flow, thus
increasing drag.
How does air affect the shot?
When a ball is spinning, air
travels farther along one
side than the other.
Air following the longer
path bends more sharply, so
the air pressure drops
dramatically on that side of
the ball.
This is known as the
“Magnus Force”
Why can’t everybody bend it?
It takes skill to find the
right combination of
spin, speed and timing!
Players like Beckham
want the ball to dip over
the heads of opposing
players and find the
corner of the goal.
So what’s the big secret?
To bend the ball, kick it
slightly off-center with the
front of your foot.
Keep your ankle bent into an
“L” shape.
Kick it hard.
Let the Magnus Force be
with you!
Can we see that again?
Click the button below to see Beckham bend it again!
Now go out and practice!