$A$ ball is thrown upwards from the top of a tower $40\,m$ high with a velocity of $10\,m/s$. Find the time when it strikes the ground (in seconds). Take $g = 10\,m/s^2$.

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. Choose the correct statement.

$A$ body is dropped from a certain height $h$ ($h$ is very large) and a second body is thrown downward with a velocity of $5 \, m/s$ simultaneously. What will be the difference in the heights of the two bodies after $3 \, s$?

$A$ ball is thrown upward with speed $10 \, m/s$ from the top of a tower and reaches the ground with a speed $20 \, m/s$. The height of the tower is ......... $m$. (Take $g = 10 \, m/s^2$)

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 upwards with a velocity of $15 \ m/s$. To what maximum height will it reach? (Take $g = 10 \ m/s^2$)