$A$ body falls from rest in the gravitational field of the earth. The distance travelled in the fifth second of its motion is ......... $m$ $(g = 10\,m/s^2)$.

Two balls $A$ and $B$ are placed at the top of a $180 \,m$ tall tower. Ball $A$ is released from the top at $t = 0 \,s$. Ball $B$ is thrown vertically downward with an initial velocity $u$ at $t = 2 \,s$. Both balls meet at a point $100 \,m$ above the ground. Find the value of $u$ in $m \,s^{-1}$. [Use $g = 10 \,m \,s^{-2}$]

$A$ ball is thrown vertically upward with an initial velocity of $150\,m/s$. The ratio of velocity after $3\,s$ and $5\,s$ is $\frac{x+1}{x}$. The value of $x$ is $...........$ Take $g=10\,m/s^2$.

The velocity of a body upon reaching the point from which it was projected upwards is:

Two balls $A$ and $B$ are thrown with the same velocity $u$ from the top of a tower. Ball $A$ is thrown vertically upwards and ball $B$ is thrown vertically downwards. If $t_A = 6 \ s$ and $t_B = 2 \ s$,then the height of the tower is ......... $m$.

$A$ stone thrown upward with a speed $u$ from the top of a tower reaches the ground with a velocity $3u$. The height of the tower is (in $u^2/g$)