$A$ ball is thrown vertically upwards from the top of a tower at $4.9 \ m/s$. It strikes the pond near the base of the tower after $3 \ s$. The height of the tower is........$m$

$A$ student performs an experiment to determine the acceleration due to gravity $g$. The student throws a steel ball up with initial velocity $u$ and measures the height $h$ travelled by it at different times $t$. The graph the student should plot on a graph paper to readily obtain the value of $g$ is

$A$ ball projected from the ground vertically upward is at the same height at times $t_1$ and $t_2$. The speed of projection of the ball is [Neglect the effect of air resistance].

$A$ particle is projected from the ground in a vertically upward direction at $t = 0$,with an initial velocity of $48\, m/s$. The distance travelled by the particle in the $5^{th}$ second is......$m$ $(g = 10\, m/s^2)$.

Ball-$1$ is dropped from the top of a building from rest. At the same moment, ball-$2$ is thrown upward towards ball-$1$ with a speed $14 \,m/s$ from a point $21 \,m$ below the top of the building. How far will ball-$1$ have dropped when it passes ball-$2$? (Assume acceleration due to gravity, $g=10 \,m/s^2$.)

$A$ juggler maintains four balls in vertically upward motion. He throws the next ball every $1/4 \, s$. For the show to continue,what should be the height to which he throws each ball? (Assume $g = 10 \, m/s^2$)