$A$ ball thrown vertically upwards reaches a height of $25 \,m$ in $1 \,s$. The ratio of the total distance covered by the ball in time $t=2 \,s$ and $t=4 \,s$ is (Use $g=10 \,m/s^2$)

If the water falls from a dam into a turbine wheel $19.6 \ m$ below,then the velocity of water at the turbines is .................. $m/s$ (take $g = 9.8 \ m/s^2$).

$A$ body falls freely from rest. It covers as much distance in the last second of its motion as it covers in the first three seconds. The body has fallen for a total time of ........ $s$.

Two stones begin to fall from rest from the same height,with the second stone starting to fall $\Delta t$ seconds after the first. The distance of separation between the two stones becomes $H$,$t_0$ seconds after the first stone starts its motion. Then $t_0$ is equal to:

$A$ ball is thrown vertically upwards with an initial velocity $u$ and reaches its maximum height in $5 \,s$. The ratio of the distance travelled by the ball in the $2^{nd}$ and $7^{th}$ second is (assume $g=10 \,m/s^2$):

$A$ ball is thrown vertically upwards. Which of the following plots represents the speed-time graph of the ball during its flight if air resistance is not ignored?