$A$ stone is shot straight upward with a speed of $20\, m/s$ from a tower $200\, m$ high. The speed with which it strikes the ground is approximately........$m/s$.

The effective acceleration of a body,when thrown upwards with acceleration $a$,will be:

$A$ body is projected vertically upward with a velocity of $20 \, m/s$ from the top of a tower of height $200 \, m$. With what velocity will it strike the ground (in $m/s$)? (Take $g = 10 \, m/s^2$)

$A$ man throws balls with the same speed vertically upwards one after the other at an interval of $2\,s$. What should be the speed of the throw so that more than two balls are in the sky at any time? (Given $g = 9.8\,m/s^2$)

$Assertion$ : $A$ body can have acceleration even if its velocity is zero at a given instant of time.
$Reason$ : $A$ body is momentarily at rest when it reverses its direction.

$A$ stone is thrown upwards with a velocity $50 \,ms^{-1}$. Another stone is simultaneously thrown downwards from the same location with a velocity $50 \,ms^{-1}$. When the first stone is at the highest point, the velocity of the second stone is $...... \,ms^{-1}$ (Take $g = 10 \,ms^{-2}$).