Neglecting air resistance, the acceleration of the ball is
the acceleration of gravity ... 9.8 m/s² downward.
It doesn't matter what you toss, what it's mass is, what it weighs,
what color it is, how much it cost, what its shape or size is, how
fast you toss it, in what direction, or how long it's in the air.
Its horizontal acceleration is zero and its vertical acceleration
is 9.8 m/s² downward, from the moment it leaves your hand
until the moment somebody catches it or it hits the ground.