Table 2.9 shows position and time data for your walk along a straight path. (a) Tell everything you can about the walk. Specify the object of refcrence. (b) Draw a motion diagram, draw a graph $x(t),$ and write a function $x(t)$ that is consistent with the data and the chosen reference frame.
$$
\begin{aligned}
&\text { TABLE } 2.9\\
&\begin{array}{cr}
\hline \text { Time (s) } & \text { Position (m) } \\
\hline 0 & 80 \\
10 & 40 \\
20 & 0 \\
30 & -40 \\
40 & -80 \\
50 & -120 \\
\hline
\end{array}
\end{aligned}
$$