$A$ body is projected with a velocity $u$ at an angle $\theta$ with the horizontal. If the time of ascent of the body is $1 \ s$,then the maximum height it can reach is (Take $g = 10 \ m/s^2$) (in $m$)

The ratio of the speed of a projectile at the point of projection to the speed at the top of its trajectory is $x$. The angle of projection with the horizontal is

When a ball is thrown with a velocity of $50 \ m s^{-1}$ at an angle $30^{\circ}$ with the horizontal,it remains in the air for how many seconds? (Take $g = 10 \ m s^{-2}$)

$A$ stone is projected from the ground with velocity $25\,m/s$. Two seconds later,it just clears a wall $5\,m$ high. The angle of projection of the stone is ........ $^o$ $(g = 10\,m/s^2)$.

$A$ 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 $^{\circ}$)

Galileo,in his book $Two \text{ } new \text{ } sciences$,stated that "for elevations which exceed or fall short of $45^{\circ}$ by equal amounts,the ranges are equal". Prove this statement.