Question

2.When you throw a ball in downward direction then acceleration in the ball just after leaving your hand is​

Answer 1

Its acceleration is -9.8 m/s^2 at the very top. On its way up the ball actually begins to fall as soon as it leaves your hand. Its weight causes it to accelerate downward and therefore its velocity decreases until it reaches 0 m/s at the top of its motion. Then, it begins to accelerate due to gravity at -9.8 m/s2.