$A$ body dropped from the top of a tower clears $7/16$ of the total height of the tower in its last second of flight. The time taken by the body to reach the ground is........$s$

$A$ balloon is rising vertically up with a velocity of $29 \,ms^{-1}$. $A$ stone is dropped from it and it reaches the ground in $10 \,s$. The height of the balloon when the stone was dropped from it is...........$m$ $(g = 9.8 \,ms^{-2})$

$A$ stone dropped from the top of a tower of height $300 \; m$ splashes into the water of a pond near the base of the tower. When is the splash heard at the top,given that the speed of sound in air is $340 \; m s^{-1}$ (in $; s$)? $(g = 9.8 \; m s^{-2})$

$A$ body is dropped from rest. It acquires a velocity $V$ after falling through a distance $h$. What distance must it fall further to acquire a velocity of $2V$ (in $h$)?

$A$ parachutist after bailing out falls $50\, m$ without friction. When the parachute opens,it decelerates at $2\, m/s^2$. He reaches the ground with a speed of $3\, m/s$. At what height did he bail out (in $, m$)?

$A$ boy standing on a stationary lift (open from above) throws a ball upwards with the maximum initial speed he can,equal to $49\; m s^{-1}$. How much time does the ball take to return to his hands? If the lift starts moving up with a uniform speed of $5\; m s^{-1}$ and the boy again throws the ball up with the maximum speed he can,how long does the ball take to return to his hands?