Answer:
30° or 60°
Step-by-step explanation:
Range of a projectile on level ground is:
R = v₀² sin(2θ) / g
Given R = 15 m and v₀ = 13 m/s:
15 m = (13 m/s)² sin(2θ) / (9.8 m/s²)
sin(2θ) = 0.870
2θ = 60.4° or 119.6°
θ = 30.2° or 59.8°
Rounded, the launch angle required is either 30° or 60°.
