Final answer:
The ball starts from rest and accelerates uniformly at 4 m/s²; after 8 seconds its velocity would be 32 m/s.
Step-by-step explanation:
The velocity of a ball after rolling down an incline with a uniform acceleration of 4 m/s² can be computed using the basic kinematics equation v = u + at, where 'v' is the final velocity, 'u' is the initial velocity (which is 0 since the ball is starting from rest), 'a' is the acceleration, and 't' is the time. After 8 seconds, the velocity of the ball would be v = 0 + (4 m/s²)(8 s) = 32 m/s.