posted by Anonymous .
The speed of an automobile increases from 11 m/s to a speed of 47 m/s over a time period of 9.0 seconds. What is the average rate at which the speed of this car is changing during this time period?
The rate of change in speed is acceleration:
a=(Vf - Vo) / t=(47 - 11) / 9=4m/s^2.