Let H(t)=-9t2+216t{“version”:”1.1″,”math”:”H(t)=-9t2+216t”}…

Let H(t)=-9t2+216t{“version”:”1.1″,”math”:”H(t)=-9t2+216t”} represent the height, in feet, of a rocket launched vertically from the ground on planet Klingon, after time t seconds. Find how many seconds it takes to hit the ground. Just write the number, not the word “seconds”.

Let H(t)=-9t2+216t{“version”:”1.1″,”math”:”H(t)=-9t2+216t”}…

Let H(t)=-9t2+216t{“version”:”1.1″,”math”:”H(t)=-9t2+216t”} represent the height, in feet, of a rocket launched vertically from the ground on planet Klingon, after time t seconds. Find how many seconds it takes to hit the ground. Just write the number, not the word “seconds”.