Question 69252
To find out how long it will hit the ground set h equal to zero and solve for t
{{{0 = -16*t^2+30*t+3}}} Solve for t using the quadratic equation
*[invoke quadratic "t", -16, 30, 3 ]
The second answer t=1.97016947761614 is the time it took to hit the ground at the point where h=0 (the negative answer doesn't make sense).