Physics
posted by Jay .
A car accelerates at a constant rate from zero to 23.3 m/s in 10 seconds and then slows to 15 m/s in 5 seconds. What is its average acceleration to the nearest tenth of a m/s^2 during the 15 seconds?

Since the final velocity after 15 seconds is 15 m/s, the average acceleration is (15m/s)/(15s) = 1 m/s^2
It's exactly like saying a car moved 23.3m in 10 s, then went back to 15m from its starting point in 5 more seconds. What is the average speed? 1m/s 
@ Steve. The answer to the question is 0.7m/s^2