A balloon is ascending vertically with an acceelration of `0.2 ms^(-2)` .Two stones are dropped from it at an interval fo `2 s`, the distance between then when the second stone dropped is (tanke g=9.i8 ma^(-2).

Options

A. (a) ` 0.4 m`
B. (b) ` 4. 9m`
C. © 19 .6 m`
D. ( 20 .0 m`.

Answer

D

Explanation

The initial relative velocity of the first stone w.r.t. second stone . When dirst stone is just dropped is zero i.e. ` u=0`.
The relative acceleration of the first stone w.r.t. second, ` a = 9.8 + 0.2 = 10 ms(-2)`.
The relative distance between the tqo stones in `2` seconds is
` S= ut = 1/2 at^2 =0 + 1/2 xx 2^2 = 20.0 m.