If a plastic sphere floats in water (density = 1000kgm3) with 0.5 of its volume submerged, and floats in oil with 0.4 of its volume submerged the density of the oil is
A
800kgm3
B
1200kgm3
C
1250kgm3
D
2000kgm3
Verified Correct Answer: C.
Physical Principles & Numerical Solution
since the plastic sphere floats on both liquids, it displaces the amount of liquid equal to its mass in each case
∴ Mass of oil displaced = mass of water displaced
ρ x 0.4v = 1000 x 0.5v
ρ = \(\frac{ 1000 \times 0.5v}{0.4v}\)
ρ = 1250k\(gm^{-3}\)
Source: Myschool Past Questions Archive (Record #28054)