$A$ 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 ........ $s$.

$A$ body is thrown vertically upward at $t = 0$. It is at a height $80 \ m$ at instants $t_1$ and $t_2$. Also,it is at a height $60 \ m$ at instants $t'_1$ and $t'_2$. Then:

Time taken by an object falling from rest to cover the height of $h_1$ and $h_2$ is respectively $t_1$ and $t_2$,then the ratio of $t_1$ to $t_2$ is:

For a particle projected vertically upwards under gravity,it travels equal distance during the $5^{th}$ and $6^{th}$ second of its motion. Find its projection speed in $m/s$ $(g = 9.8\,m/s^2)$.

$A$ ball is dropped from the top of a $100\; m$ high tower on a planet. In the last $\frac{1}{2}\; s$ before hitting the ground,it covers a distance of $19\; m$. Acceleration due to gravity (in $m/s^2$) near the surface on that planet is:

$A$ boy standing at the top of a tower of $20 \, m$ height drops a stone. Assuming $g = 10 \, m/s^2$,the velocity with which it hits the ground is ......... $m/s$.