A stone was dropped off a cliff and hit the ground with a speed of 152 ft/s. What is the height of the cliff? (Use 32 ft/s for the acceleration due to gravity.) Step 1 We know that s(t) = 1 at + vot + So. In this situation, we have a = ft/s, vo= = ft/s, and so h, where h is the height of the cliff (in feet) that we wish to find.