Answer:
A. 3s
Step-by-step explanation:
The height of the object after t seconds is given by:

When will the object hit the ground?
It hits the ground after t seconds, and t is found when
. So







3 seconds, so the correct answer is given by option a.
Answer: B
Step-by-step explanation:????
Troll
Ratios don't have to be "per" something, while rates are "per" something.
Ratios compare 2 or more values, as well as rates.