Answer
a) PQ1 = 12 m/sec
PQ2 = 14 m/sec
PQ3 = 16 m/sec
PQ4 = 16 m/sec
b.) 16 m/sec
Work Step by Step
a.) The points Q1, Q2, Q3, Q4 should be estimates and its okay if you have different answers. the y axis is distance (m) and x axis is elapsed time (sec), So slope will be speed(m/sec)
Slope PQ1 = $\frac{Δy}{Δx}$ = $\frac{80 - 20}{10 - 5}$ = $\frac{60}{5}$ = 12 m/sec
Slope PQ2 = $\frac{Δy}{Δx}$ = $\frac{80 - 38}{10 - 7}$ = $\frac{42}{3}$ = 14 m/sec
Slope PQ3 = $\frac{Δy}{Δx}$ = $\frac{80 - 56}{10 - 8.5}$ = $\frac{24}{1.5}$ ~ 16 m/sec
Slope PQ4 = $\frac{Δy}{Δx}$ = $\frac{80 - 72}{10 - 9.5}$ = $\frac{8}{0.5}$ = 16 m/sec
b.) We are deducing the answer from part a, the limits are approaching 16 m/sec. So this is the best estimate.
