## Question

The work done to break up a drop of a liquid of radius *R* and surface tension into eight drops, all of the same size, is

### Solution

Volume of big drop . If *r* is the radius of each tiny drop, the total volume of eight drops

.

Since the total volume remains unchanged, we have

Which gives, . Now, surface area of big drop = .

Total surface area of eight drops =

Increase in surface area .

Work done = surface tension increase in surface area

.

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