Question

10^6 tiny drop coalesce to form a big drop. The surface tension of liquid is T. calculate the percentage fractional energy loss.

Answer 1

Let R be the radius of big drop. Since on coalence of droplets volume remains same...

Therefore,  $10^{6}$×$\frac{4}{3}$π$r^{3}$ = $\frac{4}{3}$π$R^{3}$

Therefore, R = 100r.

Decrease in surface energy coalence,

ΔA = $A_{1}$ - $A_{2}$

     = 4π($10^{6}$$r^{2}$ - $R^{2}$)

     = 4π$r^{2}$($10^{6}$ - $100^{2}$)

Therefore, Energy realesed is

E = ΔA×T

  = 4π$r^{2}$($10^{6}$ - $100^{2}$)×T

Further you can calculate...