$A$ ball is thrown upwards. Its height varies with time as shown in the graph. If the acceleration due to gravity is $g = 7.5\, m/s^2$,then the height $h$ is.........$m$.

$A$ 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 $t$.

An object is thrown vertically upward with a speed of $30 \,m/s$. The velocity of the object half-a-second before it reaches the maximum height is (in $\,m/s$)

The ratio of the displacements of a freely falling body during the first, second, and third seconds of its motion is

$A$ stone is allowed to fall freely from rest. The ratio of the times taken to fall through the first metre and the second metre distance is

$A$ very large number of balls are thrown vertically upwards in quick succession 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 is (take $g = 10\, ms^{-2}$):-