What is the horizontal acceleration of a ball taht is launched horizontally with a velocity of 5.6 m/s?

Horizontal acceleration=0

Explanation:

Horizontal Launching

When an object is launched horizontally at a certain speed , only one force will be acting throughout the whole duration of the motion: the force of gravity. If no effect of the wind is to be considered, then the horizontal speed will not change over time. It means the horizontal acceleration is zero. Please note the vertical acceleration is not zero, it is in fact, the acceleration of gravity (0.8 m/sec^2)

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be