Answer:
-2m/s/s
Explanation:
Acceleration = change in speed / change in time
Change in speed = final speed - initial speed
In this case the change in speed was 10m/s - 30m/s = -20m/s
And change in time was 10 sec (within 10 sec)
Therefore acceleration = -20/10 = -2m/s/s
The acceleration is negative because the car slowed down (decelerated essentially) and the unit for acceleration is meters per second per second because it is the change in speed per second.
Hope this helped!
