Answer: 1.6 m/s^2
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Work Shown:
A = old velocity = 2 m/s
B = new velocity = 10 m/s
C = change in time = 5 seconds
D = average acceleration
D = (change in velocity)/(change in time)
D = (B-A)/C
D = (10-2)/5
D = 8/5
D = 1.6 m/s^2
The acceleration 1.6 m/s^2 means that the velocity is increasing by 1.6 m/s for every second.