$A$ litre of alcohol weighs

The Sun is a hot plasma (ionized matter) with its inner core at a temperature exceeding $10^{7} \; K$,and its outer surface at a temperature of about $6000 \; K$. At these high temperatures,no substance remains in a solid or liquid phase. In what range do you expect the mass density of the Sun to be,in the range of densities of solids and liquids or gases? Check if your guess is correct from the following data: mass of the Sun $= 2.0 \times 10^{30} \; kg$,radius of the Sun $= 7.0 \times 10^{8} \; m$.

$A$ vessel with a square cross-section and a height of $6 \ m$ is vertically partitioned. $A$ small window of $100 \ cm^2$ with a hinged door is fitted at a depth of $3 \ m$ in the partition wall. One part of the vessel is filled completely with water and the other side is filled with a liquid having a density of $1.5 \times 10^3 \ kg/m^3$. What force needs to be applied on the hinged door so that it does not open (in $N$)? (Acceleration due to gravity $= 10 \ m/s^2$)

$A$ bubble from the bottom of a lake rises to its surface. Its volume doubles in the process. Assuming isothermal conditions, atmospheric pressure $= 75 \, cm$ of $Hg$, and the ratio of the densities of mercury and water $= 40/3$. The depth of the lake will be ..... $m$.

Define pressure. Give the $SI$ and $CGS$ unit of pressure.

$A$ force of $F = 10 \ N$ is exerted on a surface of area $A = 0.1 \ m^{2}$ at an angle of $60^{\circ}$ with the surface. Find the pressure produced on this surface.