Answer:1/12 or 8.3
Step-by-step explanation:
The ball hits the ground when the height h(t) = 0 , so
-16t^2 + 80t = 0
-16t(t - 5) = 0
t- 5 = 0 or -16t^2 = 0 ( here t = 0 which corresponds to when ball is thrown)
t - 5 = 0 gives:-
t = 5 seconds (answer)
