The formula to show the height and time an object is in the air :

when the object hits the ground the height will become 0
so, put h(t) = 0
and simplify :

Simplfy the equation by using discrimination rule :
The general form of quadratic equation is : ax² + bx + c
and the roots are express a s :
![x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}](https://img.qammunity.org/2023/formulas/mathematics/college/rxvf73usjbbwyik14knxdemoz21vfz2ufc.png)
On compare the given equation with the general equation we get :
a = -16, b = 48 and c = 50
Substitute the value and simplify :
![undefined]()