(Solved): The displacement of a car from its starting point after t hours is given by d=f(t) miles; a graph o ...

The displacement of a car from its starting point after $t$ hours is given by $d=f(t)$ miles; a graph of the function $f$ is shown to the right. (a) Estimate the time interval(s) on which the car has positive acceleration, and explain how you identified them. (b) Estimate the time interval(s) on which the car has negative acceleration, and explain how you identified them. (c) During the first 5 hours of its journey, estimate when the car has its minimum velocity.