A particle is thrown with velocity u at an angle α from the horizontal. Another particle is thrown with the same velocity at an angle α from the vertical. The ratio of times of flight of two particles will be
For first particles angle of projection from the horizontal is a. So T1=2u sin αg
For second particle angle of projection from the vertical is α. it mean from the horizontal is 90−α
∴ T2=2u sin(90−α)g=2u cos αg. So ratio of time of flight T1T2=tan α.