Question 1156060
h=-16t^2+8t+48=16t^2-8t-48, changing all signs
hits the ground when h=0
factor out an 8
2t^2-t-6=0
t^2-t-12
(t-2)(2t+3)=0
t=2, -3/2, use positiver root of 2 seconds, answer.
{{{graph(300,300,-.5,5,-10,60,-16x^2+8x+48)}}}