a ball is thrown vertically upward from the ground its distance in feet from the ground in t seconds is s=-16t^2+144t. After how many seconds will the ball be 288 feet from the group?

Question

a ball is thrown vertically upward from the ground  its distance in feet from the ground in t seconds is s=-16t^2+144t. After how many seconds will the ball be 288 feet from the group?

jack1 · Answer

$s  =-16t^2+144t$      and   s =288
$288 =-16t^2+144t$
so turn this into a quadratic equation, then solve for t
   $  0 =-16t^2+144t - 288$
now solve this using the quadratic formula ... or factorize
 $0 = 16( t-3      )  (t-6      )$ 
so t = 3 and t = 6 is where the ball will be 288 meters high