Answer:
Speed is slightly greater than 14 m/s.
Step-by-step explanation:
The ball will under go projectile motion. The horizontal velocity remains constant while there would be increase in vertical velocity due to acceleration due to gravity in downward direction.
Using first equation of motion, after 1 s, vertical velocity will be:
v = u +at
v=0+(9.8 m/s²)(1 s) = 9.8 m/s
Horizontal velocity = 10 m/s
Net velocity:

Speed is slightly greater than 14 m/s.