Over the last century, American footballs have become much more streamlined than rugby balls. Streamlined means "minimized air flow." One science project with which to start measures the dimensions of the two balls and hypothesizes that because of its thinner shape, the football will travel farther when thrown. Students can throw both balls and then measure and record the distances the two balls travel. No matter how the ball is thrown or who throws it, there is an excellent chance that the streamlined ball will, on average, travel farther.
Passed footballs are spin stabilized projectiles. They are spun by releasing a ball from the passer’s hand end first and in such a way that the passer’s four fingers leave the ball after his thumb. Footballs can be thrown with spin either overhand or underhand. A group of student researchers, either with or without experience playing football, should be taught to throw footballs so they spin. Students can then throw a football point first with spin or sideways with or without spin. The results can then be compared. Spin does not have to be measured, and the ball can be thrown as far as each student can throw. Neither distance nor spin is measured. The comparative distance this projectile travels so as to minimize its streamlined shape or not is the point of this project.
A brief controversy occasionally erupts in rugby, which forbids forward passes, about whether lateral passes (which are allowed in rugby) are actually forward passes in disguise. Students should hypothesize about what happens when a player running forward makes a lateral, or sideward, pass. Participants can test these hypotheses by video recording a participant throwing a ball sideways while standing still, then making the same throwing motion while running forward. The laws of physics suggest that in most cases, balls lateraled while running forward will actually travel forward and land forward of the spot at which they were thrown, even though a "lateral" is a ball that is thrown to one side or backward rather than forward.
Punted footballs, which are balls kicked for distance by a standing player, may travel either end over end or in a spiral, depending on how the ball contacts and leaves the punter’s foot. Balls kicked end over end are more difficult to catch, but balls that spiral should travel farther and their landing spot should be easier to predict. Students can test this notion by throwing footballs underhand using two hands. Balls held by one end and oriented vertically to the experimenter will travel end over end. Balls held in the middle and oriented horizontally to the experimenter will spin. Students can gather data and investigate the best way to punt a football.