Water drops fall at regular intervals form a hole at the bottom of a vessel placed at a high level. The ninth drop is about to fall when the first drop just falls on the floor after being in the air for 2 second. The distance between the 3rd and the 5 th drop at the instant is :
(Taking `g = 10 m//s^(2)`)

Options

A. `(40)/(9) m`
B. `(25)/(4) m`
C. `5 m`
D. `(5)/(16) m`

Answer

B

Explanation

`H = (1)/(2) xx 10 xx (2)^(2)`
`H = 20 m`
Time interval between two drops `= (2)/(8) = (1)/(2) sec`.

Let the distance travelled by 3 rd drops is
`s_(3) = (1)/(2) xx g xx (1.5)^(2)`
Distance travelled by 5th drops
`s_(5) = (1)/(2) xx g (1)^(2)`
`Delta s = s_(3) - s_(5)`