Aball rolls down a ramp for 15 seconds. if the initial velocity of the ball was 0.8m/s and the final velocity was 7m/s, what was the acceleration of the ball?

Acceleration = (change in speed) / (time for the change)

Change in speed = (ending speed) - (starting speed)

                            =  (7.0 m/s)  -  (0.8 m/s)  =  6.2 m/s

Time for the change  =  15 seconds

Acceleration  =  (6.2 m/s) / (15 sec)

                      =   (6.2/15)  m/s²

                      =     0.413 m/s²