A body is projected at an angle θ with horizontal. Another body is projected with the same velocity at an angle θ with the vertical. The ratio of the time of flights is-
Let time of first and second projectiles are t1 and t2 respectively.
t1=2usinθgt2=2usin(90−θ)g=2ucosθgt1t2=2usinθg2ucosθg=sinθcosθ=1cotθ