Answer:
A ball thrown into the air has the most potential energy when it has reached the highest point above the ground before it begins descending. If we consider the vertical motion only beginning when the ball leaves the thrower’s hand, the ball is exchanging kinetic energy for (gravitational) potential energy. When all of the kinetic energy has been transformed, the ball begins falling, and exchanges it’s potential energy back into kinetic energy. If you ignore air resistance, the ball will land with as much energy as it began with.
