Answer:
2.83 s
Step-by-step explanation:
We are given that

When a rock reached the ground then h(t)=0


Using quadratic formula





Time cannot be negative .Therefore, negative value of t can not be possible.
Hence, the rock takes 2.83 sec to reach the ground.
I attached a picture with the answer, hope this helps :)
Answer: 1 1/3
Step-by-step explanation: Hope this helped!