A race car moves such that its position fits the relationship:

x = (5.0 m/s)t + (0.75 m/s3)t3

where x is measured in meters and t in seconds.

(a) Plot a graph of the car’s position versus time.

(b) Determine the instantaneous velocity of the car at = 4.0 s, using time intervals of 0.40 s, 0.20 s, and 0.10 s.

(c) Compare the average velocity during the first 4.0 s with the results of part (b).