A body falls freely from a height of 125m (g=10 `m//s^(2))` after 2 sec gravity ceases to act Find the time taken by it to reach the ground?

Explanation

Distance covered in 2s under gravity
`S_(1)=(1)/(2)"gt"^(2)=(1)/(2)(10)2^(2)=20m`
velocity at the end of 2s,V=gt=(10)2=29 m/s
Now at this instant gravity ceases to act
`implies` velocity by here after becomes constant.
The ramining distance which is 125-20=105 m is covered by the body with constant velocity of 20 m/s.
Time taken to cover 105 m with constant velocity is
Given by,`t_(1)=(S)/(V)impliest_(1)=(105)/(20)=5.25s`
Hence total time taken to reach the ground