The pressure at half the depth of a lake is $2/3$ of the pressure at its bottom. What is the depth of the lake in $m$?

Explain how an open-ended tube manometer measures pressure.

$A$ liquid boils when its vapour pressure equals

$A$ submarine has a window of area $30 \times 30 \,cm^2$ on its ceiling and is at a depth of $100 \,m$ below sea level. If the pressure inside the submarine is maintained at the sea-level atmospheric pressure,then the force acting on the window is ............. $N$ (consider density of sea water $\rho = 1.03 \times 10^3 \,kg/m^3$,acceleration due to gravity $g = 10 \,m/s^2$).

$A$ bubble of volume $V_0$ is released from a depth $h$ in a lake. If the atmospheric pressure is $P$ and the temperature is assumed to be constant,what is the new volume of the bubble when it reaches the surface? (Density of water is $\rho$)

The atmospheric pressure and height of the barometer column are $10^5 \, Pa$ and $760 \, mm$ respectively on the Earth's surface. If the barometer is taken to the Moon,then the column height will be ........ $mm$.