Question 104: Properties of Matter

Question

A water drop of diameter 2 cm is broken into 64 equal droplets. The surface tension of water is 0.075 N/m. In this process the gain in surface energy will be :

Accepted Answer

$$r' = {r \over 4}$$
$$ \Rightarrow \Delta E = T(\Delta S)$$
$$ = T 	imes 4\pi (nr{'^2} - {r^2}),\,n = 64$$
$$ = T 	imes 4\pi  	imes (4 - 1){r^2}$$
$$ \Rightarrow \Delta E = 0.075 	imes 4 	imes 3.142(3) 	imes {10^{ - 4}}\,$$ J
$$ = 2.8 	imes {10^{ - 4}}$$ J

Answer

2.8 $$	imes$$ 10$$-$$4 J

Answer

1.5 $$	imes$$ 10$$-$$3 J

Answer

1.9 $$	imes$$ 10$$-$$4 J

Answer

9.4 $$	imes$$ 10$$-$$5 J

Properties of Matter

A water drop of diameter 2 cm is broken into 64 equal droplets. The surface tension of water is 0.075 N/m. In this process the gain in surface energy will be :

Choose the correct answer: