Two mercury droplets of radii 0.1 cm and 0.2 cm collapse into one single drop. What amount of energy is released ? The surface tension of mercury, `T = 435.5 xx 10^-3 N m^-1`

The sap in trees, which consists aminly of water in summer, rises in a system of capilaries of radius r = 2.5 xx 10^-5 m. The surface tension of sap is T = 7.28 xx 10^-2 N m^-1 and the angle of contact is 0^@ . Does surface tension alone account for the supply of water to the top of all trees?

What is the pressure inside the drop of mercury of radius 3.00 mm at room temperature ? Surface tension of mercury at that temperature ( 20^@C ) is 4.65xx10^-1 N m^-1 The atmospheric pressure is 1.01xx 10^5Pa . Also give the excess pressure inside the drop.

Mercury has an angle of contact equal to 140^@ with soda lime glass. A narrow tube of radius 1.00 mm made of this glass is dipped in a trough containing mercury. By what amount does the mercury dip down in the tube relative to the liquid surface outside ? Surface tension of mercury at the temperature of the experiment is 0.465 N m^-1 . Density of mercury = 13.6xx 10^3 kg m^-3 .

Two insulated spherical conductors of radii 5.0 cm and 10.0 cm are charged to potentials of 600 V and 300 V respectively. Calculate the total energy of the system.

Find the amount of work done in blowing a soap bubble of surface tension 0.06 Nm^-1 from 2 cm radius to 5 cm radius.

What is the absolute and gauge pressure of the gas above the liquid surface in the tank shown in the following figure? Density of oil = 820 kg m^-3 , density of mercury = 13.6 xx 10^3 kg m^-3 , 1 atmosphere pressure = 1.01 xx 10^5 pa .

Two metallic sphers of radii 1 cm and 2 cm are given charges 10^-2C and 5xx10^-2 C respectively. If they are connected by a conducting wire, the final charge on the smaller sphere is

Calculate the amount of energy evolved when 8 droplets of water (Surface tension 0.072 N m^-1) of radius 1/2 mm each combines into one.

Glycerine flows steadily through a horizontal tube of length 1.5 m and radius 1.0 cm. If the amount of glycerine collected per second at one end is 4.0xx 10^-3 kg s^-1 , what is the pressure difference between the two ends of the tube ? (Density of glycerine = 1.3xx 10^3 kg m^-3 and viscosity of glycerine = 0.83 Pa s). [You may also like to check if the assumption of laminar flow in the tube is correct].