Science of Spin

Tony Purnell2011 GSEF

How Does Spin Affect the

Trajectory of a Kicked Soccer

Ball?

Literature Review

• Past researchers say that thetrajectory 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 curvedtrajectory, 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 impairno 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