Given that height of the object can be found using the function h(t)=-12t²+36t, the time taken for the object to hit the ground is calculated as follows:
At the time the object hits the ground, height h(t)=0. Substituting this value in the equation we get:
0=-12t²+36t
solving for t we obtain.
12t²=36t
12t=36
hence
t=4
thus the time taken for the object to hit the ground is 4 seconds
