Final answer:
Other than the launch angle of 15 degrees, a launch angle of 75 degrees would produce the same downrange distance for a projectile launched at ground level. This is due to the complementary angles sharing the same range for a given initial speed in projectile motion, with 15° and 75° adding up to 90°.
Step-by-step explanation:
The question is about projectile motion in Physics. When a projectile is launched at ground level, the range it will cover is related to the initial angle of launch as well as its speed. For a given initial speed, and in the absence of air resistance, launching the projectile at complementary angles (where the sum of both angles is 90 degrees) results in the same range. According to the provided reference material, a projectile launched at an angle of 15 degrees above the horizontal would have the same range as one launched at an angle of 75 degrees above the horizontal. This is because 15 degrees and 75 degrees are complementary angles (15° + 75° = 90°), so the horizontal distances (ranges) traveled are the same, even though their maximum heights are different.
An archer or a punter may choose the smaller angle for greater accuracy and to minimize the effect of variables such as wind. However, in situations like clearing an obstacle or hitting a target at a higher elevation, the larger angle might be necessary.