Question

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

• A. Tan 2 α : 1
• B. Cot 2 α : 1
• C. Tan α : 1
• D. Cot α : 1

Answer 1

Answer: (C)

Tan α : 1

Answer 2

For first particles angle of projection from the horizontal is α. So$T_{1} = \frac{2u\sin\alpha}{g}$

For second particle angle of projection from the vertical is α. it mean from the horizontal is $(90 - \alpha).$

$\therefore T_{2} = \frac{2u\sin(90 - \alpha)}{g} = \frac{2u\cos\alpha}{g}$. So ratio of time of flight $\frac{T_{1}}{T_{2}} = \tan\alpha$.