$11\mathrm{.}61$ A particle moves in a straight line with a constant acceleration of $-4f\frac{t}{s^2}$ for $6s,$ zero acceleration for the next $4s,$ and a

constant acceleration of $+4f\frac{t}{s^2}$ for the next $4s.$ Knowing that the particle starts from the origin and that its velocity is $-4f\frac{t}{s^8}$

during the zero acceleration time interval, $($a$)$ construct the $v-t$ and $x-t$ curves for $0t14s,(b)$ determine the position and

the velocity of the particle and the total distance traveled when $t=14s.$