Question $1.$

$(10$ points$)$

The graph below plots the position of a person as they walk. In particular, if the point $(t,s(t))$ lies on the graph, that means that $t$ seconds after the person began walking, they are $s(t)$ meters from their original location. Note that, aside from part $($d$),$ you do NOT need to justify any of the responses below. Be sure to include units in your responses.

$($a$)$ Determine the average velocity of the walker for the first second of their trip.

$($b$)$ What is the walker's instantaneous velocity $1\mathrm{.}5$ seconds into their walk?

$($c$)$ What is the walker's acceleration $1\mathrm{.}5$ seconds into their trip?

$($d$)$ Is the walker accelerating or decelerating during the first $0\mathrm{.}25$ seconds of their trip? How do you know?