Question

The initial velocity of a body thrown up at some angle to the horizontal is v₀. The maximum distance of flight is S. At what angle a to the horizontal should the body be thrown so that the horizontal distance travelled be l(l < S)? 

Answer 1

Answer:

Explanation:

If l < Smax, there exist two angles α₁ and α₂ at which, for a given initial velocity v₀, the distance of flight is equal to l. This result is obtained directly from the equation for the distance of flight  and from the well-known trigonometric relations 

sin2α = sin(180° - 2α) = sin2(90° - α).   

The distance l for a given initial velocity v₀ will be the same for the angles α₁ = α and α₂ = (90° — α). There always exist two trajectories along which a body can be projected a given distance (Fig.): a lower one corresponding to the angle α, and higher one, corresponding to the angle 90° — α.