The purpose of the defense is to physically interfere with an offensive receiver to prevent a player from catching the ball prevent the opposing offense from advancing the ball enter the end zone of the opposing team prevent the offense from fumbling

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.