From a tower of height $h$,one ball is thrown downwards with a velocity $u$ and another ball is thrown horizontally with the same velocity $u$. What is the ratio of their velocities when they reach the ground?

$A$ child stands on the edge of a cliff $10 \ m$ above the ground and throws a stone horizontally with an initial speed of $5 \ m/s$. Neglecting air resistance,the speed with which the stone hits the ground will be $.......... \ m/s$ (given,$g = 10 \ m/s^2$).

Two objects are located at a height of $10 \ m$ above the ground. At some point in time, the objects are thrown with an initial velocity of $2 \sqrt{2} \ m \ s^{-1}$ at an angle of $45^{\circ}$ and $135^{\circ}$ with the positive $X$-axis, respectively. Assuming $g = 10 \ m \ s^{-2}$, the velocity vectors will be perpendicular to each other at a time equal to: (in $s$)

$A$ ball of mass $m=1 \, kg$ is thrown from the top of a building with initial velocity $v=(20 \, m/s) \hat{i} + (24 \, m/s) \hat{j}$ at time $t=0$. The change in the potential energy of the ball between $t=0$ and $t=6 \, s$, if the ball does not hit the ground, is (assume $g=10 \, m/s^2$): (in $ \, J$)

From the top of a tower of height $40\,m$,a ball is projected upwards with a speed of $20\,m/s$ at an angle of elevation of $30^{\circ}$. The ratio of the total time taken by the ball to hit the ground to its time of flight (time taken to come back to the same elevation) is (take $g=10\,m/s^2$).

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 $g=9.8\,ms^{-2}$).