Due to air drag the falling bodies usually acquire a constant speed when the drag force becomes equal to weight. Two bodies, of identical shape, experience air drag force proportional to square of their speed `(F_("drag") = kv^(2)`, k is a constant). The mass ratio of two bodies is `1 : 4`. Both are simultaneously released from a large height and very quickly acquire their terminal speeds. If the lighter body reaches the ground in 25 s, find the approximate time taken by the other body to reach the ground.

Answer

12.5 s