$A$ ball is thrown upward with speed $10 \, m/s$ from the top of a tower and reaches the ground with a speed $20 \, m/s$. The height of the tower is ......... $m$. (Take $g = 10 \, m/s^2$)

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

An object is thrown vertically upward with a speed of $30 \,m/s$. The velocity of the object half-a-second before it reaches the maximum height is (in $\,m/s$)

$A$ 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......$m$ $(g = 10\, m/s^2)$.

Consider the acceleration,velocity,and displacement of a tennis ball as it falls to the ground and bounces back. The directions of which of these change during the process?

Two bodies of different masses $m_a$ and $m_b$ are dropped from two different heights $a$ and $b$. The ratio of the time taken by the two to cover these distances is