The horizontal range of a projectile is given by the formula R=gu2sin(2θ).
For the first projectile, the angle of projection is θ1=15∘.
R1=gu2sin(2×15∘)=gu2sin(30∘)=2gu2
For the second projectile, the angle of projection is θ2=30∘.
R2=gu2sin(2×30∘)=gu2sin(60∘)=2g3u2
The ratio of their ranges is:
R2R1=2g3u22gu2=31
Given that the ratio is 1:x, we get x=3.
Answer: 3