Step-by-step explanation:
Evaluate in the x direction to find the time it takes to land:
x = x₀ + v₀ₓ t + ½ aₓ t²
17.5 = 0 + (15 cos 40) t + ½ (0) t²
t = 1.52
Evaluate in the y direction to find the initial height:
y = y₀ + v₀ᵧ t + ½ g t²
0 = h + (15 sin 40) (1.52) + ½ (-9.8) (1.52)²
h = -3.32
The cliff is actually 3.32 meters below where it lands. Make sure you copied the problem correctly.