One stone is dropped from a tower from rest and simultaneously another stone is projected vertically upwards from the tower with some initial velocity. The graph of distance (s) between the two stones varies with time (t) as (before either stone hits the ground).

Options

A. .
B. .
C. .
D. .

Answer

A

Explanation

`s_1 (t) = (1)/(2) g t^2` (downwards)
and `s_2 (t) = ut - (1)/(2) g t^2` (upwards)
:. Distance between the two stones will be
`s = s_1 (t) + s_2 (t) = ut`
Therefore, `s-t` graph will be a straight line passing origin.