Final answer:
When a football is moving upward and rightward towards the peak of its trajectory, the work done on the football is positive. As the football falls toward Earth, the work done on the football becomes negative, as the displacement and the gravitational force point vertically downward. The ball also speeds up, indicating an increase in kinetic energy and the conversion of energy from gravitational potential energy back into kinetic energy.
Step-by-step explanation:
When a football is moving upward and rightward towards the peak of its trajectory, the work done on the football is positive. As the football falls toward Earth, the work done on the football becomes negative, as the displacement and the gravitational force point vertically downward. The ball also speeds up, indicating an increase in kinetic energy and the conversion of energy from gravitational potential energy back into kinetic energy.