➤When ball reaches its maximum height, it would possess zero verical velocity(no horizontal velocity here as ball is thrown vertically upwards) as for the instant ball will take a rest to come back as a continuous deceleration equal to 9.8m/s^2 is acting on it all the time.
Answers & Comments
┏━━━━━━°⌜* ˚ ✦⌟°━━━━┓
:C
┗━━━━━━°⌜ ˚➶ 。˚ ⌟°━━━┛