Answer
a) PQ1 = 43 m/sec
PQ2= 46 m/sec
PQ3 = 49 m/sec
PQ4 = 50 m/sec
b.) 50 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 = $\frac{Δy}{Δx}$ = $\frac{650 - 220}{20-10}$ = $\frac{430}{10}$ = 43 m/sec
Slope PQ2 = $\frac{Δy}{Δx}$ = $\frac{650 - 380}{20-14}$ = $\frac{270}{6}$ = 45 m/sec
Slope PQ3 = $\frac{Δy}{Δx}$ = $\frac{650 - 480}{20-16.5}$ = $\frac{170}{3.5}$ = 48.6 m/sec ~ 49 m/sec
Slope PQ4 = $\frac{Δy}{Δx}$ = $\frac{650 - 550}{20-18}$ = $\frac{100}{2}$ = 50 m/sec
b.) We are deducing the answer from part a, the limits are approaching 50 m/sec. So this is the best estimate.
