A cubical block of wood of specific gravity $0.5$ and a chunk of concrete of specific gravity $2.5$ are fastened together. The ratio of the mass of wood to the mass of concrete which makes the combination to float with its entire volume submerged under water is
A hollow sphere of mass $M$ and radius $r$ is immersed in a tank of water (density $\rho$$_w$ ). The sphere would float if it were set free. The sphere is tied to the bottom of the tank by two wires which makes angle $45^o$ with the horizontal as shown in the figure. The tension $T_1$ in the wire is :
The weight of a body in water is one third of its weight in air. The density of the body is ....... $g / cm ^3$
A block of volume $V$ and of density $\sigma _b$ is placed in liquid of density $\sigma _l(\sigma _l > \sigma _b)$ , then block is moved upward upto a height $h$ and it is still in liquid. The increase in gravitational potential energy of the system is
A block of ice floats on a liquid of density $1.2$ in a beaker then level of liquid when ice completely melt