Homework: Erratic Motion

The elevator starts from rest at the first floor of the building. It can accelerate at $5f\frac{t}{s^2}$ and then decelerate at $2f\frac{t}{s^2}.$

Determine the shortest time it takes to reach a floor $40ft$ above the ground. The elevator starts from rest and then

stops. Draw the $a-t,v-t,$ and $s-t$ graphs for the motion. $(28\mathrm{.}57ft)$ Use Matlab to create the graphs.