Answer
(a) Positive
(b) Zero
(c) Positive
(d) Negative
(e) $v_{av}=2~m/s$
(f) $v_{av}=0$
(g) $v_{av}=1~m/s$
(h) $v_{av}=-1.5~m/s$
Work Step by Step
(a) The segment points up (upward progression)
(b) Horizontal segment
(c) The segment points up (upward progression)
(d) The segment points down (downward progression)
(e) The segment A Starts at $x_{0}=0,~t_{0}=0$ and finishes at $x_{1}=2~m,~t_{1}=1~s$
$v_{av}=\frac{x_{1}-x_{0}}{t_{1}-t_{0}}=\frac{2~m-0}{1~s-0}=2~m/s$
(f) The segment B Starts at $x_{1}=2~m,~t_{1}=1~s$ and finishes at $x_{2}=2~m,~t_{2}=2~s$
$v_{av}=\frac{x_{2}-x_{1}}{t_{2}-t_{1}}=\frac{2~m-2~m}{2~s-1~s}=0$
(g) The segment C Starts at $x_{2}=2~m,~t_{2}=2~s$ and finishes at $x_{3}=3~m,~t_{3}=3~s$
$v_{av}=\frac{x_{3}-x_{2}}{t_{3}-t_{2}}=\frac{2~m-0}{1~s-0}=1~m/s$
(h) The segment D Starts at $x_{3}=3~m,~t_{3}=3~s$ and finishes at $x_{4}=0,~t_{4}=5~s$
$v_{av}=\frac{x_{4}-x_{3}}{t_{4}-t_{3}}=\frac{0-3~m}{5~s-3~s}=-1.5~m/s$
