From the question we come to know several important information's and based on them we can reach the desired result. Initial speed = 0 m/s Final speed = 10 m/s Initial time = 0 sec Final time = 4 sec Then Average acceleration = (Final speed - Initial speed)/(Final time - Initial time) = (10 - 0)/(4 - 0) = 10/4 = 2.5 m/s^2 So the average acceleration is 2.5 m/s^2. I hope this has made it clear to you about the procedure of solving such problems.
