Answer:
[tex]3 m/s^2[/tex]
Explanation:
I assume you are asking for the acceleration of the ball, not the velocity (in fact, the velocity is already given).
The acceleration is:
[tex]a=\frac{v-u}{t}[/tex]
where in this case we have:
v = 24 m/s is the final velocity
u = 0 is the initial velocity
t = 8 s is the time interval for the velocity to change
Solving the equation,
[tex]a=\frac{24-0}{8}=3 m/s^2[/tex]