As the thrown football exhibits mechanical energy due to its position and speed, it has both potential and kinetic energy.
Explanation:
An object stayed at rest or an object at different heights from the ground tend to exhibit gravitational potential energy. And if an object moves in a specified velocity then the object will tend to exhibit kinetic energy. Thus, if an object exhibits both potential and the kinetic energy then the object exhibits mechanical energy as it is the sum of both energies.
Here, in the present case of football thrown in the air, the ball exhibits kinetic energy when it is thrown with initial velocity and then the kinetic energy gets decreasing with increase in the height while there will be increase in the potential energy during this time.
After reaching the maximum height, the ball will fall down due to the acceleration. It increases the kinetic energy while falling down. Thus the football will be exhibiting both the energy.