If work done in increasing the size of a soap film from $10\, cm\times6\, cm$ to $60\, cm\times11\, cm$ is $2\times10^{-4}\, J$. What is the surface tension ?

An engine pumps water through a hose pipe. Water passes through the pipe and leaves it with a velocity of $2\, m/s$. The mass per unit length of water in the pipe is $100\, kg/m$. ……… $W$ is the power of the engine .

If the terminal speed of a sphere of gold (density $\ =\ 19.5 × 10^3\ kg/m^3$ ) is $0.2\ m/s$ in a viscous liquid (density $\ =\ 1.5 × 10^3\ kg/m^3$ ), find the terminal speed of a sphere of silver (density $\ =\ 10.5 × 10^3\ kg/m^3$ ) of the same size in the same liquid ……. $m/s$

Application of Bernoulli's theorem can be seen in

A hollow sphere of radius $R$ is filled completely with an ideal liquid of density $\rho $ . sphere is moving horizontally with an acceleration $2\ g$ , where $g$ is acceleration due to gravity in the space. If minimum pressure of liquid is $P_0$ , then pressure at the centre of sphere is