From $t=0$ to $t=5.00 \mathrm{~min},$ a man stands still, and from $t=5.00 \mathrm{~min}$ to $t=10.0 \mathrm{~min},$ he walks briskly in a straight line at a constant speed of $2.20 \mathrm{~m} / \mathrm{s}$. What are (a) his average velocity $v_{\text {arg }}$ and (b) his average acceleration $a_{\mathrm{my}}$ in the time interval $2.00 \mathrm{~min}$ to
to 9.00 min? (e) Sketch $x$ versus $f$ and $v$ versus $t,$ and indicate how the answers to (a) through (d) can be obtained from the graphs.