Respuesta :
h(t) = 80t - 16t²
Ground level is h(0) = 0
We want to solve for t:
h(t)= 0
80t - 16t² = 0
16t(5 - t) = 0
t = 0 or t = 5
Answer: 5 seconds
Answer:5
Step-by-step explanation:Plug in numbers for t until you find an answer. 3 is too small. Plug in 4. Too small. Plug in 5. It works