Problem $11\mathrm{.}65$

A particle moves in a straight line with the velocity shown in the figure. Knowing that $x=-48m$ at $t=0,$ draw the $a-t$ and $x-t$ curves for $t0$ and determine $(a)$ the maximum value $of$ the position coordinate $of$ the particle, $(b)$ the values $oft$ for which the particle $isat$ a distance $of108ft$ from the origin.