$A$ body,thrown upwards with some velocity,reaches a maximum height of $20\,m$. Another body with double the mass thrown up with double the initial velocity will reach a maximum height of..........$m$.

An object is projected upwards with a velocity of $100 \, m/s$. It will strike the ground after (approximately) ........ $sec$.

Balls are thrown vertically upward in such a way that the next ball is thrown when the previous one is at the maximum height. If the maximum height is $5 \ m$,the number of balls thrown per minute will be

$A$ ball is projected vertically upwards from the ground. It reaches a height $h$ in time $t_1$,continues its motion,and then takes a time $t_2$ to reach the ground. The height $h$ in terms of $g, t_1$,and $t_2$ is ($g =$ acceleration due to gravity).

$A$ stone is thrown vertically upwards with a velocity $V_0$ from a tower of height $h$ and it reaches the ground in time $t_1$. If the stone is thrown downwards with the same velocity $V_0$ from the same tower,it reaches the ground in time $t_2$. If the stone is dropped from the tower,it reaches the ground in time $t$. Find the value of $t$.

$A$ body freely falling from rest has a velocity $v$ after it falls through a height $h$. The total distance it has to fall down from the starting point for its velocity to become double is: (in $h$)