Answer:
Vx = 150 * cos 53 = 90.3 m/s horizontal speed
Vy = 150 * sin 53 = 120 m/s vertical speed
t1 = 120 / 9.8 = 12.2 sec time to reach vertical height (vy = 0 at apex)
H1 = 1/2 g t^2 = 9.8 / 2 * 12.2^2 = 729 m height risen above cliff
729 + 405 = 1134 m total height above striking point
H = 1/2 g T^2 where T is time to fall 1134 m
T = (2 * 1134 / 9.8)^1/2 = 15.2 sec
T + t1 = 15.2 + 12.2 = 27.4 sec total time in air
Sx = Vx * 27.4 = 90.3 * 27.4 = 2470 m total horizontal distance