Answer:
0 m/s²
Step-by-step explanation:
Acceleration is the change in velocity over change in time.
Velocity is the change in position over change in time.
During the first second, the velocity is 8 m/s.
During the second second, the velocity is 8 m/s.
During the third second, the velocity is 8 m/s.
The velocity stays constant at 8 m/s, so the object is not accelerating.