Two small drops of mercury, each of radius $R$ coalesce to form a single large drop. The radio of the total surface energies before and after the change is
$1 : 2^{1/3}$
$2^{1/3} : 1$
$2 : 1$
$1 : 2$
Air is blowing across the horizontal wings of an aeroplane is such a way that its speeds below and above wings are $90\, m/s$ and $120\, m/s$ respectively. If density of air is $1.3\, kg/m^3$, then the pressure difference between lower and upper sides of wings will be ........ $N/m^2$
A candle of diameter $d$ is floating on a liquid in a cylindrical container of diameter $D\left( {D > > d} \right)$ as shown in figure. If it is burning at the rate of $2\ cm/hour$ then the top of the candle will
Equal mass of three liquids are kept in there identical cylindrical vessels $A, B $ $\&$ $ C$. The densities are $\rho_A$, $\rho_B$ and $\rho_C$ with $\rho_A < \rho_B < \rho_C$ . The force on base will be maximum in vessel:-
A ball of mass $m$ and radius $r$ is gently released in a viscous liquid.The mass of the liquid displaced by it is $m'$ such that $m\, >\, m'$ . The terminal velocity is proportional to
A .......... $m/s$ speed the velocity head of water is equal to pressure head of $40\, cm$ of $Hg$ .