Q 11-09-141JEE MainJEE Main 2019 (10 Apr, Shift 2)Easy
A cubical block of side $0.5\ \text{m}$ floats on water with $30\%$ of its volume under water. What is the maximum weight that can be put on the block without fully submerging it under water? [Take, density of water $= 10^3\ \text{kg/m}^3$]
Answer: (A) $87.5\ \text{kg}$
The block's own weight is already supported by the $30\%$ that is submerged. The extra load can be supported by the buoyancy of the remaining $70\%$:
$$m = 0.7\times(0.5)^3\times10^3 = 87.5\ \text{kg}$$
Solution by Sreeraj P, M.Sc Physics