$A$ body is projected at such an angle that the horizontal range is three times the greatest height. The angle of projection is

$A$ piece of marble is projected from the Earth's surface with a velocity of $19.6 \sqrt{2} \ m/s$ at an angle of $45^{\circ}$. $2 \ s$ later,its velocity makes an angle $\alpha$ with the horizontal,where $\alpha$ is $..........$ (in $^{\circ}$)

$A$ particle moves in a plane with constant acceleration in a direction different from the initial velocity. The path of the particle will be

If a particle of mass $m$ is projected at an angle $\alpha$ with the horizontal,then :

$A$ large number of bullets are fired in all directions with the same speed $u$. The maximum area on the ground on which the bullets will spread is

$A$ projectile with speed $50 \ m \ s^{-1}$ is thrown at an angle of $60^{\circ}$ with the horizontal. The maximum height that can be reached is,(acceleration due to gravity $= 10 \ m \ s^{-2}$) (in $m$)