A car accelerates at a constant rate from zero to 25.6 m/s in 10 seconds and then slows to 14.4 m/s in 5 seconds. What is its average acceleration to the nearest tenth of a m/s2 during the 15 seconds?
10.6
To find the average acceleration, we need to calculate the change in velocity and divide it by the change in time.
First, let's find the change in velocity during the acceleration phase. The car goes from 0 m/s to 25.6 m/s in 10 seconds. So the change in velocity during this phase is 25.6 m/s - 0 m/s = 25.6 m/s.
Next, let's find the change in velocity during the deceleration phase. The car goes from 25.6 m/s to 14.4 m/s in 5 seconds. So the change in velocity during this phase is 14.4 m/s - 25.6 m/s = -11.2 m/s. Note that the negative sign indicates deceleration or slowing down.
Now let's find the total change in velocity during the entire 15 seconds. We add the change in velocity during the acceleration phase and the change in velocity during the deceleration phase: 25.6 m/s + (-11.2 m/s) = 14.4 m/s.
Finally, we divide the total change in velocity by the total change in time: 14.4 m/s / 15 s = 0.96 m/s^2 (rounded to the nearest tenth).
Therefore, the average acceleration of the car during the 15 seconds is 0.96 m/s^2.