Two objects are projected with same velocity ' $u$ ' however at different angles $\alpha$ and $\beta$ with the horizontal. If $\alpha+\beta=90^{\circ}$, the ratio of horizontal range of the first object to the $2^{\text {nd }}$ object will be :

Figure shows a projectile thrown with speed $u=20 \,m / s$ at an angle $30^{\circ}$ with horizontal from the top of a building $40 \,m$ high. Then the horizontal range of projectile is ........... $m$

The position coordinates of a projectile projected from ground on a certain planet (with no atmosphere) are given by $y=\left(4 t-2 t^2\right) m$ and $x =(3 t)$ metre, where $t$ is in second and point of projection is taken as origin. The angle of projection of projectile with vertical is .........

The horizontal range is four times the maximum height attained by a projectile. The angle of projection is ......... $^o$

Two bodies are projected with the same velocity. If one is projected at an angle of ${30^o}$ and the other at an angle of ${60^o}$ to the horizontal, the ratio of the maximum heights reached is

A projectile crosses two walls of equal height $H$ symmetrically as shown The angle of projection of the projectile is