Question

If an object is dropped from a height of 116 feet, the function h(t)=-16t^2+116 gives the height after t seconds. When will the object hit the ground?

Answer 1

Check the picture below.

$\bf \stackrel{h(t)}{0}=-16t^2+116\implies 16t^2=116\implies t^2=\cfrac{116}{16} \\\\\\ t^2=\cfrac{29}{4} \implies t=\sqrt{\cfrac{29}{4}}$