Answer:
a) 9.8 m/s^2, regular earth gravity
b) 0
Step-by-step explanation:
At the highest point of a ball's flight when kicked upward, it has stopped moving upward entirely and has not started moving downward yet. It therefore has no speed or velocity. However, it is still accelerating at a constant rate for the entire flight, because the earth keeps on pulling on it with the same force throughout. Hope this helps!