### How Does Spin Affect the Trajectory of a Kicked Soccer Ball?

```Science of Spin
Tony Purnell
2011 GSEF
How Does Spin
Affect the
Trajectory of a
Kicked Soccer
Ball?
Literature Review
• Past researchers say that the
trajectory of a kicked soccer ball
is affected by spin because of kinetic and potential energy.
Kinetic energy is used
when the ball is kicked,
and potential is used as the
ball flies through the air.
Others stated that the path of the
kicked soccer travels in a curved
trajectory, due to air resistance
Hypothesis
• When you kick the ball from the right side, the
spin will cause the ball to curve towards the
left. If you kick the ball from the left side, it
will spin towards the right. Kicking the ball
square in the center will cause the ball to have
no spin, therefore not curving its path. If you
kick the call from the top and bottom center, it
will have no spin either.
Materials
• The items used in this
experiment are:
a pair of soccer cleats,
size 5 Nike soccer ball,
and a soccer goal.
Method
• To conduct this experiment, I will take a normal
sized soccer ball and map out a nine-point grid on
the face of the soccer ball. I will then set up the
spot from the goal where I will conduct my
experiment. Once I finish, I will mark the spot and
set the ball up so that the nine-point grid is facing
directly towards me. I will then take multiple
shots from each point on the grid using the same
amount of force. After each shot I will record my
data on a diagram as well as notes. After all my
data is recorded, I will compare each shot and
find how spin affects the trajectory.
Results
• When you kick the ball on the left side, it
would spin and go to the right. Kicking it
on the right side would cause the ball to
travel to the left in a curved pattern.
Kicking in the center, top, or bottom
would just cause the ball to travel
straight.
Conclusion
• In the end, my hypothesis was correct. The results of my
experiment ended just as I predicted. The trajectory was only
changed when you kicked it on the left or right side
of the ball. Kicking it directly
in the middle would impair
no spin, causing the ball to
travel in the same path.
Discussion
• When force is applied
to the left side of the
ball, the force causes
the ball to move faster
on the left side than the
right, which throws the
ball into spinning. The
spinning motion of the
ball then causes it to
curve.
References
```