A rock dropped from a cliff falls one-third of its total distance to the ground in the last second of its fall. How high is the cliff? I'm not asking for answer, I know the Physics Forum rules, but I am totally unsure where to start. I guess I have to use the equation d = Vot + at²/2 ? Could you please give me a hand and help me figure it out, please. Hints is all I need. Thanks.