Hello all! I am prepping for my finals and going over some work I had problems with before. This one I am still struggling with finding for some reason. Any help would be appreciated! So here is the question: A stone is thrown horizontally with an initial speed of 20 m/s from the edge of a cliff. A stop watch measures the stone's trajectory time from the top of the cliff to the bottom to be 4.0 s. What is the height of the cliff? The answer is anything between 78 - 78.5 At first I tried v=d/t: 20 = d/4.0 = 80 meters. This is close, but not correct. Then I tried v^2 = vo^2 + 2ax: 0 = 400 + 2(9.8)x => x= -20.41 meters. This is also not correct. What am I not getting? Thanks in advance!