Q18 of 24 Page 75

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 × 10–3 N m-1.

Given:


Radius1 = r1 = 0.1cm = 10-3m


Radius2 = r2 = 0.2cm = 2×10-3m


Here, two droplets form a bigger drop.


So, volume of bigger drop = sum of the volumes of the smaller drops.







Now, energy released is equal to the difference in the surface energies.



Hence, of energy is absorbed.


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