Question

A stone was dropped off a cliff and hit the ground with a speed of 112 ft/s. what is the height of the cliff? (use 32 ft/s2 for the acceleration due to gravity.) ft ft

Answer 1

52 feet high I may be wrong though. do the calculations

Answer 2

We know that the moviment of acceleration due the gravity accomplish the following rules: H = Vi * T + 1/2 * g * T^2 and V = Vi + g* T where: H is height, Vi is initial speed, T is time and g is gravity acceleration Then, as we drop off the stone, means initial speed is zero, so we can calculate first the time to hit the ground V = Vi + g * T => 112 = 0 + 32 * T => T = 3.5 seconds Within that time the height dropped by the stone will be: H = Vi * T + 1/2 * g * T^2 = 0 * 3.5 + 1/2 * 32 * 3.5^2 = 196 ft So we conclude that the height of the cliff is 196 feet.