. Two particles are projected simultaneously in the same
vertical plane, from the same point, both with different speeds and at different angles horizontally. The path followed by one, as seen by the other, is
A: a vertical line
B: a parabola
C: a hyperbola
D: a straight line making a constant angle ( ≠ 90 ^∘ ) with horizontal
which is a constant. So the path followed by one, as seen by the other, is a straight line, making a constant angle with the horizontal.
Hence, the correct option is (D).