Question

A raind drop starts falling from a heigh of `2km`. If falls with a continuously decreasing acceleration and attains its terminal velocity at a height of `1km`. The ratio of the work done by the gravitational force in the first halt to that in the second half of the drops journey is
A. `1:1` and the time of fall of the drop in the two halves is `a:1` (where `agt1`)
B. `1:1` and the time of fall of the drop in the two halves is `a:1` (where `alt1`)
C. `a:1` (where `agt1`) and the time of fall of the drop in the two halves is `1:1`
D. `a:1` (where `alt1`) and the time of fall of the drop in the two halves is `1:1`

Answer 1

Correct Answer - A
Taking g as constant, work done in bogh the cases is `-mg(1000)` since the max velocity of the journey is attained at a height of 1 km, and the second half journey is travelled by max. velocity, the time taken for the second half journey will be less.