Eric throws a ball straight up in the air. When he watches the ball he notices that it goes from a very fast upward speed it slows down to very slow upward speed (positive velocity) then it reaches the top of its path and starts to fall with a very slow downward speed and increases in speed downward. This all occurs because the acceleration due to gravity is always acting downward (approximately -9.8 m/s2) on the rock through the entire path that it travels.
Since the rock goes from a positive velocity to a downward velocity, what is the velocity of the rock is at the top of the path?

Question

Eric throws a ball straight up in the air.  When he watches the ball he notices that it goes from a very fast upward speed it slows down to very slow upward speed (positive velocity) then it reaches the top of its path and starts to fall with a very slow downward speed and increases in speed downward.  This all occurs because the acceleration due to gravity is always acting downward (approximately -9.8 m/s2) on the rock through the entire path that it travels.  
Since the rock goes from a positive velocity to a downward velocity, what is the velocity of the rock is at the top of the path?