A stone is shot straight upward with a speed of $20\, m/sec$ from a tower $200\, m$ high. The speed with which it strikes the ground is approximately……..$m/sec$

$Assertion$ : The two bodies of masses $M$ and $m$ $(M > m)$ are allowed to fall from the same height if the air resistance for each be the same then both the bodies will reach the earth simultaneously.

$Reason$ : For same air resistance, acceleration of both the bodies will be same

A parachutist after bailing out falls $50\, m$ without friction. When parachute opens, it decelerates at $2\, m/s^2$. He reaches the ground with a speed of $3\, m/s$. At what height, did he bail out ?……..$m$

A body, thrown upwards with some velocity, reaches the maximum height of $20\,m$. Another body with double the mass thrown up, with double initial velocity will reach a maximum height of……….$m$

Two balls are dropped from heights $h$ and $2h$ respectively from the earth surface. The ratio of time of these balls to reach the earth is