Question

A rock is dropped off a cliff and strikes the ground with an impact velocity of 20m/s. How high was the cliff?(use a=-10m/s2)

Answer 1

Answer:

20 m

Explanation:

by the formula,

                         $2aS = V_{f}^{2} - V_{i}^2$

                         2 x 10 x S = 20^2 - 0

                         20S = 400

                         $S = \frac{400}{20}$

                          S = 20 m