8.7m
9.5m
10.5m
11.2m
Pressure at bottom (P1) = Patm + ρgh + 4T/R1__________(1)
Pressure at top (P2) = Patm + 4T/R2____________(2)
Given
R1 = r
R2 = 5r/4
So P1V1 = P2V2
(P1)(4/3πr³)=(P2)(4/3)(125r³/64)
Dividing (1) and (2)
P1/P2 = (Patm + ρgh + 4T/r) / (Patm + 4T/(5r/4))
125/64 = (ρg(10) + ρgh) / (ρg(10))
640 + 64h = 1250
On solving we get
h = 9.5m