Answer:
3.1 m/s
Step-by-step explanation:
The acceleration of the ball is given by:

where
v is the final velocity
u is the initial velocity
t is the time elapsed
Here we know:
a = 1.8 m/s^2 is the acceleration
v = 7.6 m/s is the final velocity
t = 2.5 is the time elapsed
Solving for u, we find the initial velocity of the ball:
