$A$ ball dropped from the top of a tower falls the first half of the height of the tower in $10 \, s$. The total time spent by the ball in the air is ......... $s$. [Take $g = 10 \, m/s^2$]

$A$ balloon was moving upwards with a uniform velocity of $10 \, m/s$. An object of finite mass is dropped from the balloon when it was at a height of $75 \, m$ from the ground level. The height of the balloon from the ground when the object strikes the ground was around (in $m$). (Take the value of $g$ as $10 \, m/s^2$)

$A$ body is projected vertically upwards with a velocity of $10\,m/s.$ It reaches the maximum vertical height $h$ in time $t.$ In $\frac{t}{2}$,the height covered is

$A$ ball is projected vertically up from the ground. Boy $A$, standing at the window of the first floor of a nearby building, observes that the time interval between the ball crossing him while going up and the ball crossing him while going down is $2 \ s$. Another boy $B$, standing on the second floor, notices the time interval between the ball passing him twice, during up and down motion, is $1 \ s$. Calculate the difference between the vertical positions of boy $B$ and boy $A$. (Assume $g = 10 \ m \ s^{-2}$) (in $m$)

$A$ 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........$m/s$.

$A$ stone is thrown vertically up from the top end of a window of height $1.8 \,m$ with a velocity of $8 \,m/s$. The time taken by the stone to cross the window during its downward journey is (Acceleration due to gravity $= 10 \,m/s^2$) (in $\,s$)