An object of mass 400g and density 600kgm-3 is suspended with a sting so that half of it is immersed in paraffin of density 900kgm-3. The tension in the string is
A
1.0N
B
3.0N
C
4.0N
D
5.0N
Verified Correct Answer: B.
Physical Principles & Numerical Solution
volume of object = \(\frac{400 \times 10^{-2}}{600}\)
= 0.00067m3
volume of paraffin displaced = \(\frac{1}{2}\) x 0.00067
= 0.00034m3
mass of paraffin = 900 x 34 x 10-5
= 0.3kg
weight of paraffin = 0.3 x 10
= 3N = upthrust = tension in the string
Source: Myschool Past Questions Archive (Record #27973)