A bullet is fired horizontally from a rifle at 300m/s from a cliff above a plain below. The bullter reaches the plain 6s later. (a) How high was the cliff? (b) How far from the cliff did the bullet reach the plain? (c) What was the bullet's speed when it reached the plain?

Answer 1

(a) How far can a body fall in 6 seconds? That will be the height, H, since the in initial vertical velocity component is zero.

(b) (Horizontal velocity componet) * 6 seconds

(c) Kinetic energy (1/2) M V^2 will have increased by M g H

V^2 therefore increases by 2 g H from the initial value. You don't need to know M