$A$ body is projected horizontally with a velocity of $\sqrt{2gh}$ from the top of a tower of height $h$. It hits the ground at a distance $x$ from the tower. Then $x =$

Projectiles $A$ and $B$ are thrown at angles of $45^{\circ}$ and $60^{\circ}$ with the vertical,respectively,from the top of a $400 \ m$ high tower. If their ranges and times of flight are the same,the ratio of their speeds of projection $v_A : v_B$ is:

$A$ hiker stands on the edge of a cliff $490 \; m$ above the ground and throws a stone horizontally with an initial speed of $15 \; m/s$. Neglecting air resistance,find the time taken by the stone to reach the ground,and the speed with which it hits the ground. (Take $g = 9.8 \; m/s^2$).

$A$ player throws a ball that reaches another player in $4\,s$. If the height of each player is $1.5\,m$,the maximum height attained by the ball from the ground level is .......... $m$.

Water is flowing from a horizontal pipe fixed at a height of $2\,m$ from the ground. If it falls at a horizontal distance of $3\,m$ as shown in the figure,the speed of water when it leaves the pipe is $............\,ms^{-1}$ (take $g=9.8\,ms^{-2}$).

Two particles in the same vertical plane are thrown to strike at the same time. One is thrown from the ground and the other from a height $h$ vertically above it. The ground particle is thrown obliquely with speed $u$ at an angle $\theta$ and achieves a maximum height $H$. The second particle is thrown horizontally with the same speed $u$. What is the maximum height $h$ such that the two particles strike each other in the air?