The vertical acceleration of the football is constant and equal to the acceleration due to gravity (approximately 9.81 m/s² on the surface of the Earth), which acts downward. Therefore, the vertical acceleration remains the same throughout the entire motion, and it does not change along the path of the arc.
So, the vertical acceleration is the same at all points on the arc, and it is not influenced by the time the football is in the air. The vertical acceleration is always approximately 9.81 m/s² downward, regardless of the position of the football during its flight.