Physics
posted by Adrian .
The height of a rocket is launched from a platform 12 meters above the ground is modeled by the function h(t)=4.9t^2+25t+12 where h(t) represents the height of the rocket in meters and t represents the number of seconds after launching. How many seconds after launching will the rocket return to the ground?

h(t)=0
so
4.9t^225t12=0
use the quadratic equation, solve for t.