A rock is thrown horizontally with a speed of 20 m/s from a vertical cliff of height 27 m.
(a) How long does it take to reach the horizontal ground below?
(b) How far will it land from the base of the cliff?
(c) What is the velocity (magnitude and direction counterclockwise from the +x-axis, which is the initial horizontal direction in which the rock was thrown) of the rock just before it hits the ground?