$A$ ball is dropped from the top of a $100\; m$ high tower on a planet. In the last $\frac{1}{2}\; s$ before hitting the ground,it covers a distance of $19\; m$. Acceleration due to gravity (in $m/s^2$) near the surface on that planet is:

$A$ balloon is at a height of $81\, m$ and is ascending upwards with a velocity of $12\, m/s$. $A$ body of $2\, kg$ weight is dropped from it. If $g = 10\, m/s^2$,the body will reach the surface of the earth in ......... $s$.

$A$ ball of mass $0.2 \, kg$ is thrown vertically upwards with a velocity of $2 \, m/s$. At the highest point of its trajectory:
$(i)$ What will be the magnitude of its velocity?
$(ii)$ What will be the magnitude of its acceleration?
$(iii)$ What will be the magnitude of the force acting on it? (Take $g = 10 \, m/s^2$.)

$A$ man is standing on top of a building $100\, m$ high. He throws two balls vertically,one at $t = 0$ and the other after a time interval $\Delta t$ (less than $2\, s$). The second ball is thrown at a velocity half that of the first. The vertical gap between the first and second ball is $15\, m$ at $t = 2\, s$. The gap is found to remain constant. Calculate the velocity with which the balls were thrown and the exact time interval between their throws.

$A$ juggler throws balls vertically upwards with the same initial velocity in the air. When the first ball reaches its highest position,he throws the next ball. Assuming the juggler throws $n$ balls per second,the maximum height the balls can reach is

$A$ tennis ball is released from a height $h$ and after freely falling on a wooden floor,it rebounds and reaches a height $\frac{h}{2}$. The velocity versus height of the ball during its motion may be represented graphically by (graphs are drawn schematically and not to scale):