Question 628334
A football is kicked straight up from a height of 4 feet with an initial
 speed of 50 feet per second
The formula H= -16t squared +50t+4 describes the ball's height above the
 ground, h, in feet, t seconds after it was kicked.
 How long will it take for the football to hit the ground?\
:
When the ball hits the ground h = 0, therefore
:
-16t^2 + 50t + 4 = 0
Solve this using the quadratic formula
{{{t = (-50 +- sqrt(50^2-4*-16*4 ))/(2*-16) }}}
you should get a positive solution of t ~ 3.2 seconds