$A$ stone thrown upward with a speed $u$ from the top of a tower reaches the ground with a velocity $3u$. The height of the tower is (in $u^2/g$)

Assertion $(A)$: The displacement of a vertically projected body during the last second of its upward motion is $\frac{g}{2}$.
Reason $(R)$: For a vertically projected body,the acceleration decreases gradually and becomes $\frac{g}{2}$ during the last second of upward motion.

Two spheres of same size,one of mass $2\, kg$ and another of mass $4\, kg$,are dropped simultaneously from the top of Qutab Minar (height $= 72\, m$). When they are $1\, m$ above the ground,the two spheres have the same

The distance covered by a stone dropped from the top of a building in the last second of its motion is $0.36$ times the total distance travelled by it. The height of the building is (acceleration due to gravity $g = 9.8 \ m/s^2$). (in $m$)

$A$ man drops a ball from the roof of a tower of height $400 \ m$. At the same time,another ball is thrown upwards with a velocity of $50 \ m/s$ from the base of the tower. At what height from the base of the tower will they meet (in $m$)?

Two stones are thrown up simultaneously from the edge of a cliff $200 \; m$ high with initial speeds of $15 \; m s^{-1}$ and $30 \; m s^{-1}$. Verify that the graph shown in Figure correctly represents the time variation of the relative position of the second stone with respect to the first. Neglect air resistance and assume that the stones do not rebound after hitting the ground. Take $g = 10 \; m s^{-2}$. Give the equations for the linear and curved parts of the plot.