A metallic sphere weighing $3 \,kg$ in air is held by a string so as to be completely immersed in a liquid of relative density $0.8$. The relative density of metallic is $10$. The tension in the string is ........  $N$

A cube of wood supporting $200\,gm$ mass just floats in water. When the mass is removed, the cube rises by $2\, cm$. ............ $cm$ is the side of cube .

The spring balance $A$ reads $2\, kg$ with a block m suspended from it. $A $ balance $B$ reads $5 \,kg $ when a beaker filled with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid as shown in figure. In this situation

A piece of copper having an internal cavity weights $264\, g$ in air and $221\, g$ in water. Find volume (in $cc$) of cavity. Density of $Cu = 8.8\, g/cc$

A stream-lined body falls through air from a height $h$ on the surface of liquid. Let $d$ and $D$ denote the densities of the materials of the body and the liquid respectively. If  $D > d$, then the time after which the body will be instantaneously at rest, is

A man is sitting in a boat which is floating in a pond. If the man drinks same water from the pond, the level of water in pond will