$A$ balloon is at a height of $81\, m$ and is ascending upwards with a velocity of $12\, m/s$. $A$ body of $2\, kg$ weight is dropped from it. If $g = 10\, m/s^2$,the body will reach the surface of the earth in ......... $s$.

$Assertion$: If a body is thrown upwards,the distance covered by it in the last second of upward motion is about $5 \ m$ irrespective of its initial speed.
$Reason$: The distance covered in the last second of upward motion is equal to that covered in the first second of downward motion when the particle is dropped.

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?

$A$ body is thrown vertically up from the ground. It reaches a maximum height of $100\,m$ in $5\,sec$. After what time will it reach the ground from the maximum height position?

$A$ ball is projected upwards. Its acceleration at the highest point is

Draw graphs $a \to t$,$v \to t$,and $x \to t$ for an object falling freely.