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?

If the distance travelled by a freely falling body in the last but one second of its motion is $5 \ m$,then the total time of motion is (Acceleration due to gravity $g = 10 \ m \ s^{-2}$) (in $s$)

$A$ body at rest falls through a height $h$ with velocity $V$. If it has to fall down further for its velocity to become $3V$,the distance travelled in that interval is: (in $h$)

$A$ ball is projected vertically up from the ground. Boy $A$,standing at the window of the first floor of a nearby building,observes that the time interval between the ball crossing him while going up and the ball crossing him while going down is $2 \ s$. Another boy $B$,standing on the second floor,notices the time interval between the ball passing him twice,during up and down motion,is $1 \ s$. Calculate the difference between the vertical positions of boy $B$ and boy $A$. (Assume $g = 10 \ m \ s^{-2}$) (in $m$)

Two bodies of masses $m_1$ and $m_2$ are dropped from two different heights $h_1$ and $h_2$ respectively. The ratio of the times taken by the two masses to touch the ground is (neglect air resistance)

$A$ stone is allowed to fall freely from rest. The ratio of the times taken to fall through the first metre and the second metre distance is