Answer:
Option A,D
Explanation:
For floating , net weight of system= net upthrust.
⇒(ρ1+ρ2)Vg=(σ1+σ2)Vg
Since string is taut, ρ1<σ1 and ρ2>σ2
vp=2r2g2η2(σ2−ρ1)
(upward terminal velocity)
vQ=2r2g9η1(ρ2−σ1)
( downward terminal velocity)
|vPvQ|=η1η2
Further , ¯vP.¯vQ will negative as they are opposite to each other.