a) When a football is kicked vertically upwards into the air, as depicted in the diagram below, the situation is considered to be “upwards.” It is called acceleration owing to gravity when the football accelerates in a vertical downhill direction (g).

b) As soon as the football reaches its highest point, it comes to a complete stop, and at that time, its velocity will be zero due to the continual retardation caused by the acceleration caused by gravity (g).