The graph below shows the relationship between time and distance traveled by a race car moving at a constant rate and at its maximum speed. How long did it take the race car to travel 480 miles?
Race Car Data
Distance (miles)
800
700
600
500
400
300
200
100
0
0.5 1.5 2.5 3.5 4.5 5.5 6.5
Time (hours)

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)