Which of the following phenomena is not due to surface tension?

$Assertion :$ $A$ thin stainless steel needle can float on a still water surface.
$Reason :$ Any object floats when the buoyancy force balances the weight of the object.

An air bubble of volume $1\,cm^3$ rises from the bottom of a lake $40\,m$ deep to the surface at a temperature of $12^{\circ}C$. The atmospheric pressure is $1 \times 10^5\,Pa$,the density of water is $1000\,kg/m^3$,and $g = 10\,m/s^2$. There is no difference in the temperature of water at the depth of $40\,m$ and on the surface. The volume of the air bubble when it reaches the surface will be $..........\,cm^3$. (in $,cm^3$)

In a turbulent flow,the velocity of the liquid molecules in contact with the walls of the tube is

$A$ liquid drop of density $Q$ is floating half-immersed in a liquid of density $d$. What is the diameter of the liquid drop? ($Q$ > $d$, $g = $ acceleration due to gravity, $T = $ surface tension)

Write two parts of fluid mechanics and what studies are made in them?