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

Two bodies begin a free fall from the same height at a time interval of $N \, s$. If the vertical separation between the two bodies is $1 \, m$ after $n \, s$ from the start of the first body,then $n$ is equal to:

Consider a rubber ball freely falling from a height $h = 4.9 \ m$ onto a horizontal elastic plate. Assume that the duration of collision is negligible and the collision with the plate is totally elastic. Then the velocity as a function of time and the height as a function of time will be represented by which of the following graphs?

$A$ body is released from the top of a tower $H$ metre high. It takes $t$ seconds to reach the ground. The height of the body $\frac{t}{2}$ seconds after release is

$A$ ball of mass $m$ is thrown vertically upwards. Assume the force of air resistance has magnitude proportional to the velocity,and direction opposite to the velocity. At the highest point,the ball's acceleration is

$A$ body is falling freely from the top of a tower of height $125 \ m$. The distance covered by the body during the last second of its motion is $x \%$ of the height of the tower. Then $x$ is (Acceleration due to gravity $= 10 \ m/s^2$)