A projectile is launched from ground level at 15° above the horizontal and lands downrange. What other projection angle for the same speed would produce the same down-range distance?
A)30°
B)45°
C)50°
D)75°
E)90°

Question

Quizplus · Accepted Answer

For any given launch speed, the range of a projectile launched at an angle θ is the same as that for an angle of (90° - θ). Since the initial angle given is 15°, the complementary angle that would give the same range is 75° (90° - 15° = 75°).

A Projectile Is Launched from Ground Level at 15° Above