A projectile is fired vertically upward and has a position given by $s(t)=-16t^{2}288t304$ for $0$ sts $19.$ Complete parts $($a$)-($e$)$ below.

b$.$ From the graph of the position function, identify the time at which the projectile has an instantaneous velocity of zero; call this time $t=a.$

$t=9($Type an integer or a declmal.$)$

c$.$ Confirm your answer to part $($b$)$ by making a table of average velocities to approximate the instantaneous velocity at $t=a.$ Complete the table belon:

$\backslash$table$[[$Interval$,$Slope of secant line$],[a,a0\mathrm{.}5,,],[a,a0\mathrm{.}1,,],[a,a0\mathrm{.}01,,],[a,a0\mathrm{.}001,,],[a,a0\mathrm{.}0001,,]]$

$($Type integers or decimals. Do not round until the final answer. Then round to four decimal places as needed.$)$