An observer tracks the distance a plane has rolled along the runway after touching down. Figure 1.39 shows this distance, x, in thousands of feet, as a function of time, t, in seconds since touchdown. Find the average velocity of the plane over the following time intervals: 

(a) Between 0 and 20 seconds. 

(b) Between 20 and 40 seconds.

Transcribed Image Text:

x (1000s of ft) 6 5 4 In 32 1 10 20 30 40 t (sec)